Enhanced Tracking Protection in Firefox for iOS can cause this issue for you, you can test this by following the steps on the linked page. --

Tim Maks , SUMO volunteer Please mark the answer with the right solution with "Solves the problem" to help other users with the same issue

After turned off tracking protection, I’m still having the issue unfortunately, thank you regardless.

And did you do also the step of removing cookies?

Yes, I’ve cleared my cookies (as well as clearing everything except my history) with no luck.

Hi Loke,

Are you being redirected to PayPal from another e-commerce? It could also be a redirect issue from the service provider.

Yes, this is from shops redirecting, but it seems to happen regardless of company I’m shopping with, I’m assuming this is perhaps an issue with PayPal itself then.

Uhm, yeah. I tried to make a purchase in a platform using Paypal and I was able to be redirected just fine. In case you haven't, maybe try to switch connection (mobile to wifi or vice versa) to see if it helps.