My 15 month old has always been an incredibly fidgety sleeper, she does full 360’s all night.. 
but since about 8/9 months has been sleeping 6.30-6.30 most nights bar illness or teething. However, for the last couple months she cries out for 2/3 minutes when she wakes up a bit between sleep cycles. On the monitor, she still has her eyes closed but she’s crying as if she’s upset she’s woken up a bit..! On the whole, we don’t need to do anything, she re-settles.. occasionally we go retrieve a dummy or her teddy that’s at the wrong end of her cot, but mostly not. Which is all well & good but it’s happening 5/6 times a night from 11pm onwards. We are both knackered from being woken up nearly every hour and frustrated it’s for no real reason! 
Any suggestions?! I feel like it’s kinda a self settling issue but then not really as she does self settle several times a night after a short cry