It could be a known issue already but I did not find a task filed for it.
- With Minerva skin enabled, go to any page and click on the pencil button - the editing mode will be the source mode. It's not possible to switch to VE.
- When clicking on Visual editor option, the popup informs that switching to VE is possible after saving which is not true.
- Enabling the "New wikitext mode" beta feature brings odd looking but working VE.