I've done a test here, duplicating what you've done.
If you have a LUT used in a project node, and you then save and exit the project, and rename the LUT and .LUT folder that LUT was in to something else, and then load the project again, it does TRY to load that LUT, but a log error is generated that it failed to read the shaperlut.
You are not getting a failed to read error. Your system is loading the LUT, somehow. Again, assuming that the log file you sent was actually generated after you removed the LUT.
There is a handy free Windows utility called Everything. It's a very excellent and fast file search utility. And unlike the Windows File Explorer search function, Everything actually works to search everywhere, quickly. If you don't already have that (or some other file search utility) I'd recommend installing Everything, and then use it to search for BW1_GRAIN_1.cube and see if that's lurking somewhere else on your system and Resolve is seeing it somehow.
https://www.voidtools.com/downloads/