Is the dough cooked inside? If so, then lowering the heat might not be optimal. Do you change suppliers of the cheese? Could this "runniness" come from fat rather than water?

For the set temperature(s), I got that information from the various manufacturers. For the variability in "acceptable" temperature, I did a lot of reading, and got some information from manufacturers. For only two of the machines did I use empirical observation.

@Cindy. Many folks don't have vacuum sealers and the traditional water displacement method for getting rid of air is a good choice. There are LOTS of videos and pictures all over the internet. You want me to paste a google search string?