Problem after updating to Joomla 3.9.19

Hi there,

after updating Joomla to 3.9.19 there is an error with FoxContact.

The send-button does not appear as it should.
Please see attached screenshot.

Chrome-console brings an error, please see second screenshot.

I use already latest version of Fox Contact: 3.9.8
Can you please help to solve the problem?

Best regards,
Thomas

Addition:

Seems there is a problem together with JCHOptimize.
After changing the automtic setting there to "Average" the button appears.