Dial pad answer not working or randomly greyed out calling contacts

[SB2021]

v20 update 3
chrome - 131.0.6778.86

single user constantly complaining unable to answer calls, clicks green button but does not work also complains of dial pad being greyed out when selecting a contact . Has to logoff and log on to temporarily get it working. No desk phone. Tried incognito and running in a new chrome profile.

Can see multiple logons in audit log (5 today), assume logging off/on to resolve the issue.

Any ideas what can cause this? where I can check for errors? Not seeing anything related in the machine event log.

Thanks

 

[SB2021]

Can see multiple instances of the desktop app running. I have stopped and uninstalled this, will see if that resolves.