Lasers do change over time, usually not a short time though.

I have heard of that when the tickle adjustment needs alterations. Maybe due to loss of tube gas. But a week or two would be the first time I have heard of such a short time. Try calling their service department and see if they have any ideas.

In the meantime leaving off the end rows keeps you in business.

Philadelphia, PA (Really Bensalem)

When you finally understand it completely... it changes.