Is this about Firefox on the old macOS 10.13 you appear to be using?

https://support.mozilla.org/en-US/kb/firefox-users-macos-1012-1013-1014-moving-to-extended-support

The most current version you can run on macOS 10.12, 19.13, 19.14 is Firefox 115 ESR currently at Fx 115.34.0esr.

Firefox 116.0 and later including the current 119.0 Release and 140.9.0esr requires macOS 10.15 (ten.fifteen) or later to run. Unless you can update your macOS to 10.15 or later.

If you cannot update your macOS to 10.15 or later to use the current Firefox versions, then there is something you can try to fool the bank sites like Chase into thinking you have a more current Firefox version.

1. In a new tab, type or paste about:config with a colon : in the Location (address) bar and press Enter/Return. Click the button accepting the risk.
2. In the search box on top of the page, type or paste forceVersion and pause while the list is filtered
3. Double-click the network.http.useragent.forceVersion preference to display an editing field, and change the value to 128 or 140 then press Enter/Return or click the blue check mark button to save the change.