So, the best work around for Samsung phones doesn't appear to be available on Pixel. I lock the app to always on in the recents.
Aside from battery optimization on the app itself, you might check for global settings. Not sure where that would be in a Pixel, but on Samsung, there is a setting in Device Care -> More Battery Settings -> Adaptive Battery. I have to go in and disable it after every update as they REALLY want to push this for some reason. On the same More Battery Settings page, there is also Performance Profile. I have mine set to standard. Then, backing up a page, under background usage limits, I had to turn off "Put Unused Apps to Sleep".
That fixed 95% of my problem.
Since you have Android, you might also look at using Tasker Geolocation to push your presence changes to Hubitat in case it lags.
I did my own version of this Tasker+Autolocation Presence Setup [Android Only]. My version updates a virtual presence (Actually from "combined presence" app which is the one I use for modes. So, if Hubitat is lagging, Tasker changes my virtual and Hubitat is almost always within 5 minutes of Tasker when it misses. Between the two working together, I have an issue maybe once every couple of months, if that. Usually, it is after an update or my phone compass getting out of calibration (this is Google Play Service's fault for tying compass to GPS), or because of where I live, spotty cell coverage that doesn't update HE when I change location.
