With #980 we introduced live validation and batch validation and adjusted the Theia integration so that it removes batch validation problem markers from the problem view on editor close, and only persists live validation markers in the problems view beyond close of the editor. The reason is that when the user clicks on a problem marker and the editor opens, the marker in the diagram will be available for live validation automatically, while the markers for all other validation reasons won't until the user triggers the respective validation.

For Eclipse and VS Code this problem markers removal strategy isn't implemented. VS Code removes all markers on editor close, while Eclipse keeps them all, afaik. Thus, we should align the marker removal strategy of Eclipse and VS Code with the default of Theia for consistency reasons.