Hi,
Are the uneven loops at the beginning or end of your warp?
I have a second metal bar and attach them together with just a loop at each end. On this video at 25:45 Jane has the two rods attached with loops at each end. This way, you just need to slide your warp onto your 2nd wooden bar. Hope this helps!
https://www.schoolofweaving.tv/season-1-episode-2-dressing-your-loom-back-to-front/videos/1-2-1-warping-a-loom-1-cotton-boucle-warp

I'm just wondering about the direction of the warp around the back beam.

Thank you.. same direction as always!

That's great! Do the threads between your warp separators look like they have loosened?

Yes! I think that’s the possible problem.. or it’s a fairly slippery light wool and it’s not really gripping on the lashing sticks and paper.. I’ll try to send a video!

If there are only a few threads, you may be able to hang a few weights on those threads to give it more tension. If it's the whole warp, might need to unwind until you reach where it's stable and rewind. You might need more tension on your warp when you are beaming onto the warp beam. If you're using books for the weight, add a few more :)
You can try and send the video to [email protected] if it's not too large.