cannot open certain website

iPad Pro 2016 won't open certain website(s).

New problem, just this week.

Earlier this week, I was able to enter the site (autofill) after a failure and yesterday, it worked just fine, all this without any other actions.

Fully updated iOS, deleted and reinstalled app, "user name or password incorrect."

However, iPhone 6 and iPad mini sign in without problem.

I've reset, cleared the history.

I verified username and password on settings on both iPad and iPhone

What else do I do?

iPad is kept up to date