The bot refused to buy because the min effective margin was set not to make a loss.

Therefore, the bot did exactly what you told it to do.

Once again, I suggest trying out different combinations of parameters using the paper trading version. There are a number of parameters that you can adjust and play with to ensure swings you want to catch are not missed. But remember this has an associated inherent risk. If for example you accept a 1% loss on a down swing and the course doesn't swing back up, you have lost 1%. No bot can avoid that...

All the best,
The leonArdo guys