Doubt this is linked to your reason, but seems worth mentioning here.

Does min DJI stake size change throughout 24 hour period?

I had Rejections last night on 2 separate Systems and Reason was Min Stake Size = 2 (Systems were set at Stake Size = 1)

Edit / PS

I just noticed … the System tried to place an Order every 1 Second for 11 seconds … is this normal on a 5 Min TF??  I thought code would be read once at the end of each 5 Min bar??