It seems that Immigration is now rejecting online 90 Day reports when your last TM30 registration was not in the place where you are living/applying.
My last TM30 at the place where I live dates from January 2020, before Covid. Since then I've only traveled within Thailand and this was never a problem with 90 day notifications, also not for my most recent one 3 months ago.
But today the system gave me a 'rejection' because it found that my most recent TM30 registration was close to two years ago in Bangkok. This is interesting because I stayed in a whole lot more places since then all over Thailand, but I guess none of those did a TM30 report. 😉
So... People may want to think twice about checking into hotels with their passport because that means having to do another TM30. Which for some people is a hassle when they have to ask a landlord to visit the immigration office, etc.
(Of course if you have a login to the online TM30 site or app then it takes just 2 minutes to do another TM30 when you return after a holiday, so it's just a minor hoop to jump through. )