If this is the case it would seemingly indicate that you need to identify something else that has changed in the stove's environment.But it has worked well this way for about 10 years, without a problem.
Have you purchased a moisture meter yet ?
Have you made any changes to your home since successfully using the stove last? For example. New windows, doors, siding, weather sealing, addition?
Have you added any venting fans to the home? Stove hood vent? Bathroom vent? Dryer?, New HVAC components, appliance's ?
Have you tried starting the stove with the nearest door or window open?
Add a pic of your chimney termination in relation to the house roof.
Your stove looks like a Century product to me. A better pic of the tag may identify the exact model.