wr21 lost connection

I have a number of WR21 systems in the field (20+). Only one of them has the following behavior. On weekends and sometimes on Friday, the system will lose it’s cell connection. Light status is:

Power light ON
Service light blinking 3 times
WWAN light blinking 5 times
Signal all 3 lights lit.

It will not connect to it’s attached RTU (BL2100), but a power cycle fixes the issue and it will run for another week or so. This is the only unit that has this problem. The others are solid. I feel that it is an ATT issue/cell tower problem, but any help would be appreciated.

I am unable to access the logs locally, but will set up a remote link so that I can access remotely. These units are heavily firewalled.

Thanks to Scott, Zach and Bill Word for help with past issues. Been able to fix them all with their help.

Thanks, David Eaton

Hello David

I have the same issue in 10 devices of a total o 60, can u share with me how do you fix this issue? … thanks in advance.
Abraham