Air bubbles in sugarpaste

Make sure the whole cake is wet/sticky before you put the sugar paste on it. If you have ANY little bits that are too dry, the fondant doesn’t stick to them and that’s where you get the “bubble”.
Sometimes they don’t appear straight away so you can’t see them until it’s too late.
Hope this helps x

P.S maybe use apricot jam or piping gel instead of water to wet the cake? I find the jam works best (use sieved jam diluted with a little boiling water)

Is your cake cold when you put the fondant on? Another tip would be let the cake sit out a little bit and warm up before you put the fondant on.

Thanks for the replies I will try anything to see if it helps . I leave my cake overnight on the kitchen work top I do not put my cakes in the fridge .

Use an acupuncture needle to prick the bubble and ease air out. I buy packs on eBay and they don’t leave a pinprick.