Browser refuses all attempts to log on to Ebay.co.uk

I cannot log on to Ebay.co.uk account at all. Comes up with repeated “I am not a computer” boxes ( as many as 10 of them!). It was a bit edgy for a few days but since the last Microsoft Win 10 Pro update it is impossible to log on. I can log on if I use Chrome or Firefox but no chance with Avast browser. There is no new update showing so I am at a loss as to what I can do and still use my favourite browser. Any help would be appreciated by this pensioner in the UK.

I have just logged in to my ebay.co.uk account without issue.

Avast Secure Browser is up to date - Version 81.0.4054.114 (Official Build) (64-bit).
My OS is win10 Home 64bit 1909 version and latest May cumulative update.

I have pretty much a default installation of ASB.

Do you have any additional extensions installed ?