Microcracks in freshly painted rim

Hello @ all, I used to paint my rims myself a few days ago when it was still so warm. I used Dupli Color Aerosol and Dupli Color 2 layer of clear varnish (did stupidly think it was 2K clear varnish) Since it was the first time, I was really quite satisfied.. When I looked at them today, I noticed that with one very clearly and with the other a little less small micro cracks have formed.. First I thought it was the spray sealing, then sanded with 2000er wet and felt it a little better but unfortunately still visible when I light up with a flashlight. I have no idea why that is so, maybe it was the 2-3 days now just too cold on the balcony and the varnish is torn?! I also don’t look quite through whether it is the base or the clear varnish.. Strangely also, that it happened only with two.. Well, I wonder now what I should do. My Tend enz would be just another can of clear varnish, after I grind it with 1500 and hope that nothing will burst up. If the cracks are still visible, it is just so.. Or do you have any special tips? Thank you very much!