+1 I am having the same exact issue on my Pepwave Max Transit running firmware 8.1.1 build 5040.
I have deleted and recreated 2.4G SSID’s and they appear for a minute then drop. None of our 2.4G devices can find the network. All 5GHz devices find the network without issue. I have separated the SSID’s (creating one for each broadcast type) and that didn’t resolve the issue either.
Anyone ever hear back on a fix? Thanks!
UPDATE MAY 30TH, 2021 4:33PM PDT
It appears that by changing the settings for the 2.4GHz network to a single channel (Channel 5) from “Auto” that all the devices that only work on 2.4GHz suddenly see it being broadcast! Have tested it and found it to be stable thus far. I’ll post again in a week after some time on the road and advise as to it’s long term stability. Now, I know this is ideal so I have also reached out to the reseller for their opinion on the matter.