Haven't been up that way myself but big cat sightings around the Shropshire hills go back decades, there's a decent amount of documented reports if you dig around. Kent gets a fair few too and I've always thought these things follow certain routes - possibly ley lines or just natural wildlife corridors, hard to say.
What did it look like exactly? Panther-black or more of a dark grey? Size matters too, a big domestic gone feral looks very different to something genuinely exotic. Would be good to get more detail before anyone starts jumping to conclusions either way.
If you were near Stiperstones or Long Mynd that area has some interesting history with strange sightings generally, not just big cats.