After upgrading to lastest software release v2.4.3.131, I was unable to browse the devices, apps, rules etc. as it was really slow and sluggish on my PC, it would take ages to load or not at all (both Edge and Firefox were same).
Anyone else experiencing this issue?
However, browsing on my mobile, S25 ultra, was okay.
I have now rolled back to beta version 2.4.3.130 and I can now view devices and apps, UI seems to be okay again.
My C7 & C8 are OK using Chrome and Firefox.
Thanks for checking.
I've just upgraded back to 2.4.3.131 and it seems to be okay again, so not sure what the issue was previously.
I'll be adding a Settings toggle to disable the chatbot, in case it causes problems or if someone just doesn't like it hanging around the UI.
Thank you looking into this issue!
I've just pressed the "toggle chatbot icon" and now the UI is hanging again.
Restart seems to fix it temporarily, but the issue is back again after a short period, I guess I will have to downgrade and upgrade the software again. Look forward to your fix.
Sorry, can't help - haven't run into any issues w/.131 being sluggish...Win 11/Chrome latest. 
I did run into some major sluggishness, but in automations rather than in UI. However, a reboot of all my hubs (I have 3 main production hubs) seems to have resolved the issue. Keeping an eye on it.
Things still appear to be working at normally warp-speed for me, both automations and accesing the hub UI.
I should note that your wife has mentioned similar to-do list sluggishness on your part, resolved by poking you in the ribs and giving you "...that look..." which generates a quick reboot on your part. Maybe your hub is picking up your bad habits? 
Automations are having issues. Some devices aren't getting commands to turn on or off, although the logs show the commands being sent. UI appears to be a little slow responding at times.
I did a shutdown, pulled the power cord and booted back up after 1 min. That didn't help. I also did a soft reset to an older version before 131 (not through Diagnostic so it didn't change back to the previous version number) and still have the same issue.
Waiting for a fix.
Yep, I am also having issues with my automations.
I had not initially noticed as most of my critical automations are replicated in other systems so things will continue to run and work even if I break my main hub, C8 Pro.
This morning, for the first in a long time, I noticed that the whole house ventilation system and the dehumidifier in the bathroom was not working properly as the humidity readings were not being updated properly (or delayed or high and still not working), I thought this may have been due to me switching for the first time from the community matter bride driver to the default system driver. Will need to investigate further to confirm, but I am guessing that this may be related to the UI issues (although my CPU and memory seems to be okay, spikes are the restarts) and not due to the matter driver itself.
EDIT: upon checking the rules, it seems that I had not updated the humidity sensors correctly after deleting and recreating devices with system matter driver. So, assumption made above regarding automations not working correctly is not accurate, but the humidity sensors not updating values in a timely manner was correctly observed. So, will need to investigate Matter system driver vs custom driver further.
Just got home and I could not access the hub locally using the IP address from a PC (firebox browser).
Access was fine from my mobile phone, S25 ultra, so I have now downgraded the software to v2.4.2.157 - and I can access the hub locally again from the PC once it rebooted, hmmm.
Will monitor and see if symptoms persist on this version,
Can you PM me the hub id? I'll check the engineering logs on the hub. Got a couple more of these reports, trying to figure out what's causing them.
2.4.3.133 < Seems very good not [slow and sluggish] at all
Seems much better then : [2.4.3.131] C8-Good Job Guys !
After some observation on my Mesh Network, I belive the cause of the issue of UI sluggishness and/or no access to C8 Pro on local network from a PC was due to a network routing error where both WiFi and Ethernet connections were enabled at the same time.
It seems that ethernet was not taking priority and disabling the WiFi connection.
Note that I was able to use both WiFi and ethernet hub IP addresses from my mobile phone and access the UI, but it was not possible from my laptop/PC.
The problem was resolved after clearing or "disconnecting" from the WiFi network in Network settings as I was always connected via ethernet and WiFi was accidently enabled at some stage.
Thanks for this, it helped me get up and running again.
I'm (was) connecting to an ethernet port on a mesh extender. After upgrading to 2.4.3.133 I started getting the slowness. Downgraded back down to 2.4.2.143 but it didn't help.
I managed to have enough patience to get to the network page and removed the wifi setting (which I also didn't remember I had enabled) but still no relief.
I shut down the hub and moved it to where I could connect directly to my router and boom, it worked. For fun, I went back to the extender and it didn't work, back to the router and it works great.
Upgraded again and it's still working connected directly to the router.
Interesting through all this is that when both the web UI and app were sluggish or not responding at all, all my controls, buttons, lights, apps, etc. continued to function. Just something about getting at the gui (Dagnostics Tool also slow but functional) broke, even after downgrading.
Anyhoo, thanks for this. I was banging my head against the wall and would have never gone down this path myself, probably.
I'm having severe performance on 2.4.3.131 and subsequent releases. WI-Fi is not enabled, Ive disabled Sonos App and devices.
Rebooting every 15 minutes, yes I know I can disable that feature.
I have 3 other hubs running on this release just fine. Just this C7 has the issue.
In diagnostics under advanced, I rolled it back to 2.3.7.146 - wow that was along time ago, old UI. But at least it performs well.
Any further suggestions on this issue?
Simon
You can download the latest 2.4.2 using /hub/advanced/downloadPlatform/242 and switch to it in the diagnostics tool. The same URL can download all recent firmware versions (e.g. latest 2.4.1 build = 241 in the URL, etc.).
The endpoint gives no progress indication and takes a few minutes. It will say "done" when download has finished. Just let it do the work.
Also, please PM me the hub id this happened on. I'll check the engineering logs.
Download the Hubitat app
