I have this samsung oven and recently noticed that the oven will not maintain temp. It gets up to temp but then dramatically drops off and will not get back up. I see lots of people complaining of the same issue, but no fixes posted. Do not want to spend a bunch of money to have a tech show up and throw parts at it. If this is a common issue I would think that it would be in some bulletin or an experienced tech will have seen this before and know what to do. Please help

Thanks