Actually I did. Start with this article: DST Root CA X3 Expiration (September 2021) - Let's Encrypt
You must not be getting Windows updates (as is the case with me) for it to break. Otherwise an update would have already downloaded the ISRG Root X1 root cert. Chrome, strangely, uses Windows's root certificates, while Firefox manages its own. So FF works no problem. Here is what I did: In FF go to: about:preferences#privacy and scroll to Certificates. Click View and then find ISRG Root X1 root cert. Export it, it will be saved to, say, your Desktop. Then just import it to your Trusted Root Certificate Authorities store in Windows (it's easy, just google it quick). Worked like a charm for me.