Hi swm84mm,
Couples thing to verify accoridng to the error message you are receiving:
1) When plugin the card into the Mac machine, access into KeyChain Access and check if the certificate is valid and trust properly?
2) As you mentioned, you have tried both Chrome and Safari. Can we verify if any of these browser works?
3) If it fails on Chrome, please access into the Browser Settings -> More tools -> Developer tools -> Security
Please check if the certificate is valid or not from the location above.
Please keep us posted. Thank you!
Ivan