Map disappears from website and preview

Hello,
I am having an issue using Mapster WordPress Map plugin on my website. The plugin is great and worked super well until it broke down. I have set everything up and somewhere within developing other pages on the site – the map stopped working.
It disappeared from the website, where it used to work properly, and what’s weird – the preview of the map is gone from the settings panel. Nothing is showing. Why it is weird -> I can see the preview within the locations just fine.

I was using MapBox API (all in order), but now I am also trying MapLibre, but it doesn’t help. MapLibre, same as Mapbox loads fine in the Locations settings.

I tried: changing the map provider, creating a new map, deactivating/reactivating the plugin, updated the plugin to the latest version.

Some things I did that might have broken it (don’t want to disable, unless necessary): installed Polylang to make the web multilingual, created a child theme.

I am extremely thankful in advance for any leads on how I might be able to fix this.

J