Hello martinp876,
Could you take a look at the following post:
https://forum.fhem.de/index.php/topic,84372.msg962588.html#msg962588
It seems tmr-RESIDENTStk_DurationTimer does not get cleaned up from %defs{global}->{helper}->{bm} which account for a daily memory increase in Fhem.
I have 3 different presence devices (Rm_Heidi, Rm_Sen, Res_Landsroem) but they are not aggregated correctly. Apptime creates a new entry for every RESIDENTStk_DurationTimer instead of increasing the count for each of the 3 devices.
https://forum.fhem.de/index.php/topic,19040.msg962804.html#msg962804