UI freezing, webcam works in standalone

What is the problem?
UI command window/tab locking up

What did you already try to solve it?
Different browsers, opening webcam in window by itself
Logs (octoprint.log, serial.log or output on terminal tab at a minimum, browser error console if UI issue ... no logs, no support!)
Noting interesting in Octoprint.log. Job started, user logged in
2020-06-11 17:21:05,636 - octoprint.printer.standard.job - INFO - Print job selected - origin: local, path: speednut_0.2mm_PLA_MK3_2h25m.gcode, owner: _api, user: _api
2020-06-11 17:21:05,656 - octoprint.util.comm - INFO - Changing monitoring state from "Operational" to "Starting"
2020-06-11 17:21:05,668 - octoprint.printer.standard.job - INFO - Print job started - origin: local, path: speednut_0.2mm_PLA_MK3_2h25m.gcode, owner: _api, user: _api
2020-06-11 17:21:05,680 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2020-06-11 17:21:05,698 - octoprint.util.comm - INFO - Changing monitoring state from "Starting" to "Printing"
2020-06-11 17:21:21,630 - octoprint.server.util.sockjs - INFO - Client connection closed: xx.xx.xx.x1
2020-06-11 17:21:27,917 - octoprint.server.util.sockjs - INFO - New connection from client: xx.xx.xx.x1
2020-06-11 17:21:28,040 - octoprint.server.util.flask - INFO - Passively logging in user userid from xx.xx.xx.x1
2020-06-11 17:21:28,042 - octoprint.access.users - INFO - Logged in user: userid

Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible)
Octoprint version 1.4
cat /etc/octopi_version : 0.17.0
Raspberry Pi 3b+, RPi camera.
Firefox browser 77.0.1 (64-bit)
Windows 7 Pro OS

I'm printing from Prusa Slicer direct to the printer's Octoprint on a Raspberry Pi. RPi is connected via wired ethernet, USB to Prusa MK3s. Prints work fine. The UI is becoming unresponsive though. The video is setup for 720p 15fps. In a seperate browser window [IPaddress]/webcam/?action=stream works fine. Very little lag, maybe a little chppy but I think that's due to 15fps. Back on the UI though, if I access the control tab, the UI freezes. Updates maybe every 20 seconds. If I wait patiently sometimes I can get it to move off the control tab to a different tab. Sometimes it seems to lockup completely. Watching "top -d1" on the Pi, the Pi doesn't seem to be sweating it, reportinging 95% idle. I can start the UI at gcode, watch the gcode fine, and it's OK, move to temperature, still OK, move to the control tab and it goes out to lunch. Appears to be it's video window causing it. Once I've accessed the control tab, subsequently waiting and moving back to the gcode tab, it too is unresponsive, and laggy.

I have no active plugins that I know if. Action command prompt and Bed levelling guide are listed in setup.

Is there some setting I can do to fix this?

I have the same Problem. Webcam works if used in standalone, but control tab lags out the whole browser tab, sometimes not even the browsers debug consoles opens up. Every other tab is fine, most of the time.

Whats really weird is that on some occasions its works without any lag. When it's happening, neither restarting the octopi server, restarting the raspberry pi nor closing the browser nor any combination of those seems to fix it. After some times it just magically works again...

Any pointers on where to search?

Yeah I also got that when I use a high quality stream. Seems like a browser issue :confused:

Are you also using firefox?

I too have had issues with the Web UI freezing/locking up. I had originally associated this with having the Pi run too much. After seeing your browser thoughts, i tried Microsoft Edge (i hate edge) and it works floorlessly!

New edge is basically Chrome with a slightly different theme at this point, sold to you by a different company.