Email Newsletter Template with individual font

Hi,
I created and saved an email newsletter template in Wix Studio using the Google font ‘Montserrat’ for the text blocks. This font is included in the editor’s list of font styles in the ‘Individual fonts’ section.
(I know that some email clients do not offer Google fonts and will replace them with system fonts, but that’s not the issue.)

The problem is that:
When I create a new email campaign using my newsletter template with Montserrat, the font settings are initially displayed correctly.

However, if I select all the text in a text block and type new text or replace the text by copying and pasting (or copying and pasting without style), the font settings of this text block are overwritten and reset to standard text (Helvetica, with a different size and alignment).

However, if I only edit some parts of the text (e.g. changing some words or keeping at least one letter in my predefined “Montserrat” style), the type settings remain as defined in my template.

Question: How can I ensure that the font settings do not get overwritten when I edit or replace the entire text in a text block?