MR5200 Endless Searching for Signal

Have MR5200 for last two years. Worked mostly flawlessly on GSM data services in a dozen countries. In May upon return to USA, new FW updated and since then we have been "Searching" for signal more than 60% of the time. We have two different data sims (t-Mobile and Google Fi(I know piggy back, so not always different)), but while either sim will have 5 bars of 5g in a phone in the same location, the MR5200 says "Searching" about 50% of the time.  IF it does get signal, it is very slow, <30mbps. 

Is this solely a FW problem, or a bigger problem with the device?

Thoughts and help please.