Which title deed info do we go with? Right of Way dispute

Hello,
I’m hoping for a little help because we want to build a little garden office at the back of our garden, but there’s a small access point to the neighbour’s garden that means we’d have to make it smaller than we’d want.

when we bought our property in 2018 we were told there were two right of way paths for the neighbouring house (we’ll call it #21). One is at the front of the garden and goes from theirs to ours and down the side alley. The other is around 10ft down at the back of the garden (it’s a small garden) and goes down a right hand path to the same back of house path and down the side alley. When we saw our title deed it only had the front right of way listed and it noted a 1958 conveyance and 1922 agreement between the two properties. It doesn’t mention the back right of way at all and isn’t drawn on the title map either.

We have since had a new neighbour move in and thought this might be a good opportunity to ask if we could get rid of that back access but she says she wants it just in case she could afford to build a structure in the back in the future. I asked the previous owner of #21 if there was any restrictions on which way the door needed to swing or how big it needed to be and if the path needed to be where it was. She shared her title deed and the historical 1958 conveyance which has the path clearly marked. However, we noticed that hers is dated 1994 where ours is dated 1995. Does this mean that ours is actually the correct file and there is no back right of way? I’m curious as to why the two are different in the first place. Do we have a case to say that it’s not actually a right of way because our deed doesn’t have it but does recognise the front one explicitly and mentions the historical agreements. Surely if the back one was still there it would mention that one too.
I wondered if since the previous owner of #21 used it for 26 years if it could be claimed anyway or would that not be the case with a new owner.
Any advice is appreciated. My new neighbour is an agricultural property solicitor and I don’t want to be misinformed if we have a slightly awkward chat. I also want to remain friendly so would prefer to be knowledgeable and not confrontational. If it came down to it we’d rather remain friendly good neighbours than have a court situation etc.