vtt loading problem

whenever i load up the vtt after 20 mins roughly it makes me reload the page by not updating or loading anything then once i refresh the page it says no map selected but also wont let me select any of the maps. 

ive reloading the page fully. signing out and logging back in. I've tried incognito mode that worked for an hour then the same issue. ive tried other browsers but i had the same issue. ive cleared my cookies and extensions but the I've had the same issue

does anyone have any ideas on how to fix this issue or know what's happening 

This has been happening me every time on my desktop computer. No VPN, no extensions, hard acceleration enabled, cache cleared. But it works FINE on my laptop. But for some reason on this big two monitor computer it can't load the VTT. sometimes it will load 1 time for 15 minutes but if I click around too long it freezes or forces a refresh and then never works again. this has been a problem for months. Sucks and makes planning sessions hard.