While I can't say I've had mine running for several months, I am having a similar issue with CP only. I can install docker and everything appears to work fine, however after a little bit of time, if I try to refresh the webui the page comes up blank (white) or unable to connect altogether.
It seems that something, whether it be a setting or some other scan/upgrade attempt that is messing with the webui's ability to load. I won't dismiss user error on my end, however your situation seems to be similar.
Interested if anyone else is having a similar issue with the webui.
Note: Using Needo CP docker.