Ahh that would explain why I could never monopolize a mature market.

its not realy a bug.

In order for the employees of the manufacturing departments to "learn" the new tech lvl, they are downgraded 1 level. Since manufacturing units dont lvl up as quick as purchasing/sales departments, you either have to lengthen the period of R&D of that product, or put more into the training of that factory.

In my experience once the factories are needed to lvl up in order to meet demand, i set the R&D of that product to 3 or 5 yrs. Demand is already higher, so the tech lvl of that product is good as it is. Also the 3 or 5 yrs give the manufacturing departments time to lvl up to lvl 3 or 4 orso.

Every time I invented new technology, my manufacturing level automatically reversed back to level 1. It's so costly especially when I have invested so much in training to get to level 9.