Custom styles are not displayed when updating block

Hello, one question, please:
I have updated some Gutentor blocks (Post Widget) after edits and their custom style has disappeared (styles are visible on edit page but not displayed). I thought there might be some conflict with the customizer styles but but definitely not, it has only happened in the blocks that I have updated, in the rest of the blocks the styles are displaying correctly.
What could be the problem? Thank you.