When I remove a tubeless tire with sealant, I like to hang the tire on something so it's suspended, keeping the sealant at the bottom of the tire. If I try leaning the tire on something, it usually bends over against its own weight and the sealant pours onto the floor.

Did you make sure to orient the wheels in different directions to make sure you got the sealant distributed well?

I will also say the first time I taped some tubeless rims, I did a less than stellar job, and had air loss. I ended up redoing it after cleaning and drying the wheel really well and had success.