Welcome to the forum. You will find a wealth of knowledge here. Fellow members have saved my bacon many times. If it can happen to an RV it has happened to someone on this forum. You might also look for a specific Shasta owner's forum.
Cute unit! I looked it up on the net. Shasta has been in business for a long time and have a good reputation.
You can check the slide alignment yourself. This can be done either when putting it out or taking it in. When the slide starts to move look to see if either the front or back of the slide start to move before the other. Stop about halfway and measure the distance from the side of the unit to the outside edge of slide. The measurement front and back should be very close.
If it is out of alignment, it is a fairly simple fix. It should take less than an hour depending on the slide mechanism and location. The torn seal may have to be ordered.
Just an FYI. Dragging slide can also be a sign of a major defect such as an out of square slide out room. Don't mean to scare you. A vast majority of us have many, many cycles on our slides with no problems.
Just stay on top of the issue and keep us informed.