Withdrawing from Robo

Hi alll, I'm thinking of withdrawing from my robo (currently using Stashaway). I have about 12k in total and I'm probably quite a bit in management fees.

I wanted to find out what typically signals it's time to withdraw? Are there specific profit percentage targets you guys usually use? My current portfolios seem to be ok (not in the reds but also not really making sense for some) so I want to get some tips on the best criteria for assessing when to withdraw