Just a wild guess, but it seems that people with an "older" TM30 are being asked to do a new TM30 with the new reporting system for just about any transaction. While people with "newer" registrations are not or maybe it's just a crap shoot.
For those who own or those who have helpful landlords, getting a new TM30s is easy. Those with foreign landlords who don't live in country find it not so easy, regardless of what the rules strongly suggest as being the responsibility of the landlord.
When I become the head of Immigration, there will be a single TM77 which is a combination of TM30 and TM47. 55