satyr Could be a glitch.. Like this one nearby in my area. Plant upgraded to mid-split in 2022, yet this one home in the middle is stuck with 1200/35 as the max speed offered, despite all of the other homes having access to 2000/200 (now 2000/300) since the end of Q4 2022. All homes connected to the same HFC plant. Not a glitch relating to the FCC broadband map either, xfinity.com is only offering speeds up to 1.2 Gbps.
Gosh, if I was a customer at this address, I would wonder what I need to do in order to correct/fix this! It would suck to have my address stuck at 1200/35, years after my neighbors have been enjoying mid-split! But who knows, maybe the system would fix itself when it realizes that my modem which would be registered to my Xfinity account with my address on file is connected to a mid-split plant.

The good news is that AT&T deployed fiber to this neighborhood in Q3/Q4 2024, with speeds up to 5 Gbps offered over a XGS-PON infrastructure. AT&T Fiber is Competing with Comcast Mid-Split installed 2 years prior, SpaceX Starlink, Verizon 5G Home Internet, and T-Mobile Home Internet (depends on availability). As a new resident, maybe I would just let Comcast classify my address at 1200/35 forever and I would just sign up for AT&T Fiber!
Just a example of how all ISP’s can have issues regarding availability data. I have seen the same issues with AT&T Fiber in some cases, submitting an F-Case ticket at the local corporate store does get the address marked as serviceable if it was mis-marked as non serviceable before (of course, the address does need to be physically serviceable in order to get green-lit).