SSL_ERROR_BAD_MAC_ALERT (Firefox)

Firefox Browser has been giving me this warning from time to time (if I reload the page / click "Try Again", the page is accessed normally) Secure Connection Failed An error occurred during a connection to pokefarm.com. SSL peer reports incorrect Message Authentication Code. Error code: SSL_ERROR_BAD_MAC_ALERT The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. Please contact the website owners to inform them of this problem. I haven't noticed a pattern in when/where it appears... But always immediately on opening a page (a shop thread, a Pokémon's summary, and the Scours page were when it happened for me specifically) I'm pretty sure I first got it at least at 23:00 server time 01/Apr, maybe a couple of hours earlier than that Not sure if it's tied to the recent report about antivirus warnings, but I don't use Avast/AVG

It may help if you can give a full screenshot of the error page you're seeing, just in case it reveals anything, but that's weird...

I'm back with screenshots: The "Learn more" brings to a mozilla support page about this kind of error: https://support.mozilla.org/en-US/kb/secure-connection-failed-firefox-did-not-connect?as=u&utm_source=inproduct While the "Not secure" opens this: And below is the "more information": Like the other few times, if I reload or click "Try Again" it immediately brings me to the page and the connection is shown as secure and encrypted as usual I have uBlock Origin on Firefox but it's disabled, I'll see if clearing cookies changes anything