FIXED (NOT a Gantry problem): Uncaught TypeError: jQuery(...).spectrum is not a function

[GudrunRau]

Joomla 4.4.0 Gantry 5.5.17 Helium Template
I wanted to allow users to edit acymailing newsletters in frontend. Button did not work. If I switch of the Gantry 5 system plugin editor works fine. But this is not a solution.

The following error appears when selecting the "Edit email" button:
Uncaught TypeError: jQuery(...).spectrum is not a function
This seems to be related to the color picker library or its integration with jQuery in the editor_wysid_utils.min.js and jquery.min.js files

The Acymailing Support says: this seems to be a problem with Gantry5 and Helium Template. What kann I do?

[GudrunRau]

Fixed: Thank you to Viktor. Found a workaround with Acymailing Controllers