I recently picked up some Conti GP 5000 s TR tires and Silva sealant hadn’t arrived, so I fit the tires the way I always do—using 60ml of Stan’s sealant (non-race)—but tires were losing heaps of pressure (>10psi after 2hr ride, and about 50% pressure overnight on multiple rides and nights). I have a video (attached) of the air leaking out of the sidewalls underwater, and not the bead, so I knew the issue was not a bad fit or a valve. Never had this problem with the GP5000 TLs, but while I was fighting this issue and reading about others with the same problem, the Silca sealant arrived. Couldn’t get the Stan’s out fast enough. I replaced it with the Silca sealant, and problem immediately solved. I’m so relieved.