pbass

I have a 2019 Kona Rove ST I bought new, and the bike spec said the rims were "WTB Asym i23 TCS". Well, getting tubeless tires (all WTB--Byways, Ventures, and now Senderos) to mount to these rims has been a nightmare every time. I've never once been able to do it myself - I have one of those Blackburn pumps with the compression chamber, and have even tried the gas station high powered air pump. Always had to take it to the LBS. The last time, it took 2 guys wrestling it for an hour to get the then new Senderos to mount.
So, the Senderos have been on now for a year, and I just popped one side off because something was clogging my valve, so I could clean it out. Now, that side will not mount again. I took it to the LBS and they tried for a good while and basically gave up---they said these rims don't appear to actually be tubeless compatible. That would certainly explain why it's always been a struggle and apparently just luck when they do actually mount. They were sold as "TCS". However, the rim does not say "TCS" anywhere on it. See the pic. Is it the case then that these really aren't TCS rims?

https://konaworld.com/archive/2019/rove_st.cfm


EDIT: I also tried a different tire, the Venture that had previously been on it, and still no luck. Tried the soapy water trick...nada.