RF 100-500 tripod ring won't tighten sufficiently

[jkphoto]

I have recently purchased an RF 100-500 lens and am very happy with its performance so far.  However, the tripod ring does not seem to tighten sufficiently to prevent the lens/camera from rotating.  Any advice/solution would be greatly appreciated.

[drac]

Note that after a week or so, my lens was loose again. There is a DPReview thread that includes a video on how to disassemble things further to tighten some internal screws, but that is not guaranteed to work. Others have used shims. As you can see from my reply below, I went with @March411's recommendation and picked up the iShoot Lens Collar, though I wound up getting it off Amazon. Nice and snug now!

[March411]

Odd, works perfectly for me in Firefox

[drac]

It seems to have been a short lapse. I use Firefox as well, and the edge server from Cloudflare that was hosting the iShoot website was being called out by Cloudflare as unavailable for about 2 days. Now I can access it as well 🤷🏻‍♂️. In any case, thank you for the pointer to iShoot and their collar!