I always had a hard time sealing tubeless road tires after they had been used, and removed for cleaning. A few times I had to use a new tire even though the old tire had many klm left. I tried straps, soapy solution, pressing the tire into the rim, a compressor, nothing worked. I was always able to seal the new tires with a floor pump.
The combination was Shimano tubeless rims with Hutchinson fusion tires.
Once I changed to Conti tubeless I was able to seal used tires using a compressor..