Create triggers with timers, notice when trigger value is updated and configuration cache is reloaded then timer count grows and reindex takes time, however no one update triggers, they just changed value, problem-ok, problem-ok.

2088741:20251016:133646.377 zbx_dc_sync_configuration() reindex    : 0.218057 sec 24000112 bytes.
...
2088741:20251016:133646.377 zbx_dc_sync_configuration() timer queue: 600002 (806485 allocated)

Expected:
I only have 300k triggers there shouldn't be more than 300k timers but they grow more and more when value is updated.
There shouldn't be frequent allocations/deallocations as in my case 24 MB, it takes time and can cause fragmentation.

Fix:
Check that expression and recovery expression did not change and don't add new timer in this case, continue using old one to avoid allocations.