Never seen that before. Suggest try a hub reboot using the settings menu. Or try to create a new dashboard in case this one has become corrupted somehow.
I used the dashboard before I left yesterday, it was ok but that would've been local then. I will likely have to go there (4 hrs roundtrip) to troubleshoot, but idk what to look for, other than go/no go. The speed of the hotspot does not appear to be an issue, given that upload video is quite acceptable. I saw a few others experienced the okhttp3 error, but no real solutions I could see.
I was able to solve this error and can now access the dash remotely. switched the hubitat to a faster repeater / extender (tp-link re350) and put the camera on the other extender. So far both (hubitat and cameras) are working (remote access) with the changed config. appeared to be timing issue as app could see the hub - but it was quite consistent.