Just replaced my 1222 moen facut in the bathtub because it got clogged up and would not allow hot water to pass through. All went well but now I can not get it to stop dripping in the off position. Everything else works fine just keeps dripping. I tried losing the handle, I looked to see if it had an o-ring on the back and it does not but nor did the one that was in there before and it did not drip. Any help?

Something's preventing the cartridge from seating.
Try this. Shut the water off and remove the cartridge. Now turn the water back on to flush out the supplies and valve body. Reassemble and test. Better now? Tom