If it’s a red emitter, it’s not a CREE XRE. Cree never made a red XRE. I went through the same situation when I got an HS-802, and mine appeared to be a clone emitter. See this post : https://budgetlightforum.com/t/-/24083#node-27896
As was mentioned earlier, a Cree xpe-2 on noctigon/sinkpad is what you want. The UF-T20s I have modded were between 1.4 and 1.75A, and performed well with decent runtime.
As far as your stated problem, it sounds like the emitter isn’t properly affixed to the pill as was mentioned earlier, or it could be a bad driver like I found in the HS-802.
If you want to disassemble, loosen ring around the lens. After lens is removed, you can get to the LED and pill, which is threaded as well. Take it apart and snap some pics for us.
Let me know if I can help.