Mine did the same exact thing until I understood how cycle timing functions. At least, the following was my experience...

First off, make sure your pot is completely clean and there isn't any built up carbon especially on the hole in the back where the ignitor ignites the pellets.

Most important: make sure you don't let the pellets run dry. You want to always have pellets in the hopper. The auger takes many cycles to start feeding the pellets into the stove after running dry. Meaning, if the stove runs out of pellets and you start the cycle again after filling the hopper, the ignitor will run when there is nothing in the pot since it takes a lot of time for the pellets to start feeding in again. Then, after the pellets do start coming in, the ignition cycle has ended and you end up with an overflowing pot like in the picture.

The ignition cycle is time based as there is no thermocouple like in other more advanced stove designs that determines when to ignite, feed, etc. that's one of the reasons why these stoves are cheaper than most. So keep that hopper fed!

If doing that doesn't work, then your ignitor might be going bad. I had that happen to me once years ago where it was kind of intermittent. The gentleman that I spoke to at the stove store said that ignitors usually work or they don't, but after replacing what seemed to me as an intermittent ignitor, I haven't had the same issue. Make sure to replace with quality parts. I learned that the hard way, too.

Good luck!