After upgrading to OH 3.1.0.M3, I just realised that the Modbus binding stops polling / updating item states for some items. No changes to setup besides updating OH. Strange though, as some items update as before, whereas some don’t, without any logged issues. Also strange, as the issue appears for Data things within the same Poller, i.e. one Data thing working as before, one Data thing stops updating.
For reference: Using Modbus TCP.