There are MS120 switches that have a (small) chance on hardware issues at the chip level, resulting in neighbouring ports like 10/11 or 2/3, seeing eachother. Resulting in spanningtree blocks, and UDLD errors, and ports having intermittent connectivity.
This issue is acknowledged by Meraki, but in the case i have opened Meraki can not give details like production batches or serial numbers of switches that are sensitive for this bug.
We have an organizaton with 500 MS120-24P switches, where now around 15 - 20 switches are hit by this bug. These switches are around 3 years in use at the customers sites now, production - i guess - around beginning or halfway 2020
I wonder if anyone here has experienced this issue and has more details.