The mvp has a deep well 510 connector & a tall walled ego connector.
This makes for quite a few delivery devices that just don't fit well and causes various problems.
Some experience connectivity problems others experience airflow issues.
If you're trying to eliminate the gap between the k1 base & mvp by over tightening the connection you will block the air inlet.
The k1 uses the ego threads, the high wall ego connector on the mvp blocks the air inlet when over tightened.
The is no such thing as 'all the way on' with that set up, it is a balance between tight enough to make the electrical connection but lose enough to still allow airflow.
Try tightening using the drip tip as a guide, holding only the drip tip when threading onto the mvp, when the drip tip slips/spins it is tight enough.