Trigger stops after one loop for no obvious reason

I want to write some data to a file 30s after the race status changes to Result.
I use a trigger to set variable 'restim' to now_time when race status becomes Result.
I then use another trigger to detect when 30s has elapsed before writing to the file. However, when it reaches this calculation it only ever runs once and nothing else subsequently appears in the logs. (See log below. This is the first and only time the calculation is ever run - it should continue until 30s has elapsed). The trigger is set to All Markets. Any ideas why? I must be missing something but no idea what!!

14:10:09	Checking market "Horse Racing / GB / Lingfield 5th Mar / 14:02 Lingfield 5th Mar - 2m3f Hcap Hrd".
14:10:09	Checking condition and Selection's Trigger Expression winner_name is equal to sel_name.
14:10:09	Selection: Ito Ditto, initial expr.: winner_name, intermediate: ItoDitto, final: ItoDitto.
14:10:09	Selection: Ito Ditto, initial expr.: sel_name, intermediate: ItoDitto, final: ItoDitto.
14:10:09	Condition is: TRUE. valid for 1 selections: Ito Ditto.
14:10:09	Checking condition and Selection's Trigger Expression (now_time-restim)/mf_second is greater than 30.
14:10:09	Selection: Ito Ditto, initial expr.: (now_time-restim)/mf_second, intermediate: (45356.5903890-45356.5903877)/0.00001157, final: 0.
14:10:09	Condition is: FALSE.

Hello,

Triggers are executed on market refresh only.
There is no refresh after market become settled.