Hi
I think these problems are because the trigger has not yet received an up-to-date list of bets from the exchange. A couple of things you can try:
Check your settings for the frequency of updating the list of bets and see if speeding up the bets refresh rate improves things.
Most example triggers that bet and cancel etc. have a time delay built in to ensure enough time for an action to be registered on the exchange and the list of bets returned to MFP.
In each betting action: record now_time in a user variable e.g. last_bet_time
In each subsequent betting action add a condition: (now_time - last_bet_time)/mf_second is equal or greater than 3
this will ensure enough time to get a fresh list of bets from Betfair before executing the next action
Here is an example trigger where this method is used and is described in detail (towards the end)
https://marketfeeder.co.uk/learn/triggers/classic-scalping/