Can't use Paypal on eBay

Recently, I have been unable to complete payment using Paypal in the eBay checkout on my PC (Chrome is my preferred browser). In the checkout I choose Paypal as preferred payment method. The Paypal popup appears, I log in with my password. The "complete payment" button appears, and when I click it, it does nothing. I checked my Paypal and thankfully it took no money. This has happened for every attempted payment for the last week. Previous to this issue, I have made thousands of payments using Paypal through eBay.
I can, however, make payment using Paypal through eBay on my Galaxy s21, and have to do that to finalise purchases.

To pre-empt the usual questions:
- Yes. The card linked to my Paypal is the correct card number and all details are correct.
- Yes, I have more money in my account than is required to make payment.
- No. I haven't clicked any weird links that scams use.
- No. There has been no update to either Windows or Chrome since the last time Paypal actually worked, to the instance it didn't.
- I have remove all cookies, cleared my cache and deleted all temporary files.
- I checked that Paypal wasn't blocked or exempted in both my browser and firewall.

Any help would be great !