Automation - re-send notification every X seconds

You’re welcome.

Regrading the errors. You should use default for filters ( here |int) wherever you can. Esp. as they are thowing errors, if there is no value and you don’t use them (new for some releases, before it returned 0 or input value or …).

So have a look here

and use e.g.

states (‘sensor.water_mb_window_sill_battery’) | int(default=0)

soem for floats, etc. etc.