Retroarchievements for certain systems listed as "unsupported"

[retropieuser555]

RPI4 - 2gb
Retropie 4.7
Retroarch 1.8.8
lr-mupen64plus-next & lr-pxsc-rearmed

So I encountered this yesterday, for certain emulators and games, N64 and PS1 specifically, certain achievements are listed as "unsupported" whereas ones next to them will be marked as "locked". The example I've got is Ocarina of Time. I tested this on Retroarch 1.8.9 on my mac with the same rom and the achievements are all listed as "unlocked". I also checked the Retroarchievements forum and it appears people had this error but and it was fixed by updating to Retroarch 1.8.9. https://retroachievements.org/viewtopic.php?t=10666

It's odd as I can't find the issue on any other emulators and it's not every game either (Crash 2 for me has them listed fine, all "locked")

So my question is, has anyone else noticed this and if anyone has manually updated to Retroarch 1.8.9 or 1.9.0 is there any steps outlined for that. As the retroarchievements forum suggestion of updating Retroarch seems to solve this problem (although granted I imagine the reason we're not on them already is because they may have other bugs related to Retropie & pi hardware)

Edit: So I used @BuZz 's fork from github and I'm now on Retroarch 1.9.0 but it still has the same problem, so it might be something that's up with the retroarchievements

[retropieuser555]

So it doesn't appear to do this for lr-parallel-n64 or lr-mupen64plus oddly, so at a guess it seems there's something specific to those 2 cores.