In shortcode “&” is replaced to “&”
I have found 2 different cases.
1. Page (without GP sections mode)
When the editor mode is switched from Text to Visual and back to Text.
You can then correct the shortcode in Text Mode and everything works.
I use only Classic Editor (with plugin “Classic Editor”).
Settings: Default editor for all users: Classic Editor;
Allow users to switch editors: No.
2. Page (with GP section mode)
I created a GP section. I’ve inserted a shortcode. Saving.
Then I open the section content in Text Mode (GP section content opens in Visual Mode by default) and see that the shortcode is changed.
You can’t correct the shortcode in Text Mode. After correction and section saving, shortcode anyway is changing.