I just tested the current script version on Google Chrome (v. 101.0.4951.67, 64-bit) with Tamper Monkey (v. 4.16.1) and it works for me without any issues.
IMDb might be serving you a different page, or there might be errors in the data it is sending you.
If you can provide more details I might be able to help. Please see the How to report errors (so they can be fixed) page and post the details below.
My guess is that IMDb was doing a slow rollout of the changes, because I just got the new format as well.
Thank you both for reporting and suggesting changes. I did at least a couple more changes than Ghosted suggested: a few to solve names not being highlighted, another to try to find the title even if IMDb changes the formatting again (as long as it keeps using thetag).
Version 1.51 should be live now. I'll close this issue now, but let me know if it works (or don't) for you.