I had the exact same problem last week but luckily it turns out my employer provide a service where you can download copies of your previous payslips- check with your employer to see if they can re-issue?
But as above really, from what I could gather it all depends on the lender. I would imagine a letter or some sort of communication from your HR dept outlining your salary and all the rest of it would be your best bet if you can’t get your payslips.
For sure you wouldn’t expect a lender to deny a mortgage to a decent customer purely on the strength of one missing payslip, if everything else is present and correct.
I’d imagine you’ll be fine but then I’m no expert.