I have four RX200's. Admittedly, not the RX200S model.
I have been,using them upwards of six months, since I bought my firts one.
I do not own a Wismec tank or atty. I use Aspire Triton and Atlantis, Uwell Crown, Eleaf Ijust2, Eleaf Melo 3, Vaporesso Gemini (Ccell version) SMOK TFV4, and a couple other tanks on them. (No Kangertech though; they leak too much)
I've never had a problem with any of the mods or tanks.
NOWHERE in the instruction booklets for the mods does it say to ONLY use a Wismec atty or tank. If I was restricted to an RDA dripping atomizor, I would not have bought the mod. I have less than zero inteserst in building my own coils. I have even less interest in dripping. I drive truck, I'm guessing dripping and driving do not go well together. I want more than a couple puffs before the juice is gone.
I did have a "no atomizer" error once, when I replaced a (genuine) Triton coil. I replaced that coil, and it worked fine. That one coil must have been bad.
If you have not done so already, change the coil, and/or try a different tank/atty.