Using Windows 7 and Firefox I see web sites like Costco & Home Depot denying access, but others like Amazon allowing access. Is this patchwork of access due to the loss of support for Windows 8.1 and earlier?? using Firefox and Windows 7. Is this

'''Yes it is. ''' If you have access to a newer computer with a more recent version of Firefox, test it and it should work. Here are other win 7&8 user with similar issues on various sites. https://support.mozilla.org/en-US/questions/firefox?tagged=windows-7&show=responded