“Blog Designer” makes Tables look crazy with “Hestia” theme

Before I deactivated “Block Designer” our table(s) looked crazy, like this:
https://ibb.co/7CJ2Rb3

After I deactivated it looked normally.

This only happens in combination with the Hestia theme, the standard themes work fine. Some experts on WordPress IRC raged against the CSS code of the plugin, I don’t remember it precisely, but it was something about a “rule” which affects the entire page. The example I showed them was an “empty” table which only had column names but empty columns. The columns were squeezed to the left, even at the cost of needing two lines for the column name. There was a slightly colored rectangle behind the table which had a lot of empty space to the right.

We’d like to keep using this plugin for our “current pages” section.
Can you suggest an alternative plugin in the meantime or a quick fix?

Best regards, Tobi + our chess club