Hi @mousepad
okay i understand - but for this spinning wheel issue - there should be a multiple reason for this .
Here i am sharing github link where this issue is actually reported and couple of solution is given by users - https://github.com/magento/magento2/issues/2933
That might help you , also another reason is speed of server - as you mention when you clear cache and do all the stuffs , it is working - so it might be depends upon server speed as well.
still to debug more - share a error log with us , also check browser console and share its details with us - that might help us to troubleshoot the issue.
Hope it helps !!
if issue solved,Click Kudos & Accept as Solution