Shropshire keeps coming up in these reports and I don't think it's coincidence. That whole stretch from the Long Mynd down toward Wenlock Edge has had big cat sightings going back decades, way before anyone was paying attention online.
My cousin lives near Church Stretton and she's seen large paw prints twice in the past year, bigger than any domestic animal has any right to produce. She's a farmer, not someone who dramatises things, and she was pretty shaken both times.
The terrain out there is perfect for something like a melanistic leopard or a large feral. Dense bracken, plenty of deer, not that many people wandering off the main paths. If you're going to have a genuinely established population of out-of-place big cats anywhere in Britain, Shropshire is honestly one of the more credible locations.
What were the exact conditions when you spotted it? Time of day, distance, how long you had eyes on it? That stuff matters a lot if anyone wants to take this seriously and actually investigate properly.