I recently received a VB-R-099 frame and wheel set from Velobuild. I'm sure I'll have some questions as I get into the build but here's one for now...

This is my first time using tubeless tyres. The front tyre went on quite easily. The rear was more of a struggle but after several attempts and the use of some soapy water, I got the tyre mounted using only a track pump. However, when I deflate it, it will become unseated from the rim (it will re-inflate easily and appear to be well seated although I don't get the 'pop' sound). Both tyres lose pressure over several hours but I'm assuming this will be solved after I add sealant. I've tried leaving the tyre inflated at 100psi for 24 hours and it still becomes unseated when I deflate it.

Is this a problem? Or should I just get on and add the sealant without worrying about it?