Kahler bass tremolo stability issues

Hi there, this is my first time posting, but have been a long-time lurker in this community.
A few months ago I had a flat-mount Kahler 7410 tremolo bridge installed in my bass guitar by a luthier. Initially it operated correctly, although about a week later I began to notice my strings always going sharp after pulling up on the arm (happens with even the tiniest tug). Pushing down on the bar then will return the strings back to pitch. This has been a consistent problem that hasn't gone away.
I've done a fair amount of research into trying to find a solution for this problem but can't seem to narrow down the cause on my own. To figure out if the strings are being snagged by the nut, I apply graphite lubricant, and also after diving on the arm I've tried tugging/yanking on the string behind and around it, to no avail. Its very unlikely that the strings are being held up there. In addition I also have Sperzel locking tuners installed (which I profoundly would recommend to just about everyone).
So.. then it seems to me most likely that the problem area with this stability issue must be coming from the cam system of the Kahler. I am now wondering if I should try lubricating any of the parts, though I've read multiple (sometimes self-contradicting) statements online warning against doing that.
Any suggestions of how to correct this problem would be greatly appreciated!

Thanks!

PS: Oh almost forgot to mention, I replaced the old springs with brand new ones myself, yielding no discernible change whatsoever. Same for adjusting the tension.