You changed the priority on them a few months ago, and your total number of engineers in the country has increased the last few months. However, the main issue I see is that your education index overall is low, and falling. This effects the quantity of professionals you will train, but it also effects your welfare index.
I suggest reading the following old, but I believe still accurate article on the welfare index. I would recommend an education index of closer to 130, with other indexes as required to bump up welfare.
https://www.simcountry.com/statdocs/indexes_the_welfare_index.html