RX3 beat / BPM drift - feels like DJing with a crap belt-drive turntable..?

Having major issues with simple beat matching.. Kinda feels like I'm back to Day 1, even though I've been DJing on and off for 25 years.. The issue is simple. Tracks just drift off BPM like it's a disease with the software or hardware I don't tend to use Beat Sync as I'm prepping for pro performances where I may be using 1000 mk2s and I'm not sure they have a Pro Link (or we it's called). And obviously beat matching is more fun anyway I play fairly old school trance, so these tracks are rich, dense and a pain to even hear clearly let alone mix on beat. Back in the day with 1210s, the BPM at the very least would be pretty rock solid with only very occasional pitch adjusts (usually bc you didn't prep the BPM right) However with the RX3 and any other Pioneer CDJ/XDJ we have the BPM staring us in the face. 133 is 133, right? Well, it appears not, as I'm having to regular nudge or pitch adjust tracks mid mix, creating a bit of a stressful nightmare. Why would 133 bpm suddenly NOT be 133 bpm? It's absolutely insane and the chances of trainwrecking are amazingly high with so-called "Pro" gear..? I experimented with the tracks. I use WAVs (for sound eq) and 41 (or is it 44) sample rate. I figured there might be an issue with 48. Obviously WAVs are not VBR. Yes, these tracks are older but surely Rekordbox / the hardware is happy that a given bpm is the actual bpm right..? So why the heck am I fighting the RX3 like it's a crap old turntable? The RX3 has been updated very recently so it can't be that. All I will say is that when I was playing more modern techno tracks about a year or so ago, I seemed to encounter this less..? Is Rekordbox just incapable of correctly analysing older tracks for some reason (we're only talking classic trance from 25 years ago.. Beats are beats, right?) Any help would be appreciated and this is really stressing me out and making me pretty anxious about playing these tracks live. Thanks.