Nuking a can of Progresso soup?

If you are heating the whole can of Progresso soup in an extra large mug, that should take at least two minutes on high. Stir about half way through the cooking time. If you only heat part of the can in a regular size mug, be sure your microwave is set on high. The 1 minute 45 second should heat the smaller mug of soup. You should also stir it half way through the heating time. It distributes the heat.

"Nuking a can of Progresso soup?"

Basically it sounds like your microwave is failing. The main part is where most likely failing now known as the magnetron, or the part that excites the molecules of fluid, that causes them to heat up. I would strongly recommend not using it at all, until you have replaced it. Otherwise you could create an electrical fire. The microwave, fall all intents and purposes, be considered unsafe for use, and a potential fire hazard.

My new microwave is not nearly as high powered as my old one was. I have to double the time I used to heat or cook things in this new one. Check the power level of your oven and maybe you need to give your soup more time to heat. Also these microwave ovens do lose power over the years of service if used really frequently! Then you need to add more time as the oven gets older!

If it's tepid In my experience I put it back in for a bit longer.

Each microwave is different (wattage) - if you are using a different MW (work vs home) that could account for the difference too.