SSL DPI Firefox Error

Doing some testing with SSL Deep Inspection with FortiOS 6.4.6 and getting this error on Firefox (89.0.2) when connecting to Facebook:

SSL_ERROR_BAD_MAC_READ

Certificate is imported correctly on the Win7 PC, and I do not get the error when using Chrome. I have verified in the Browsers that the Fortinet SSL certificate is being used.  Other websites like Reddit are working correctly in Firefox with the Fortinet certificate. If I add Facebook to the Exempt addresses, it works correctly on Firefox.

Any ideas?