Bingo!! for a tire to blow off rim with no external pressure (static in garage) is more than unusual. I'm patiently waiting for op to perform inspection of wheel and tire "tonight". I would assume there is a defect in tire, wheel or more plausible, installation or size compatibility between rim and tire, which would cause tire to come off the rim whether it had a tube or not.

rim tape, sealant, or amount of sealant will not cause tire to explode off rim, only help prevent leak down and to fill small punctures while riding. For the tire to leak down several pounds in only a couple hours, especially with the proper amount of sealant, is indicative of a problem, and would have telltale signs of sealant extruding from where it was leaking.

tire and rim manufacturers would not, I would hope, put a product on the market with such a liability.

If you don't want to run tubeless tires don't, but the sky is not falling.