I haven't experienced that problem recently, or on this board, but I've had the problem before. Somehow advert malware had corrupted the browser on my android phone. I think it came from a public wifi I used on holiday. After struggling with it for weeks, I solved the problem by formatting the phone and reinstalling the operating system. It's quite an undertaking, so if you think that's beyond you, maybe consult a young relative or a professional.
If the problem is on a pc, it's probably a bit easier.