Not really. They got priority but not exactly at the expense of other fields. There was a lot of agricultural and biological sciences done, even electronics and civilian computer science too. And obviously mathematics. You probably haven't heard enough of it because Russian science was not named after Russian scientists too often in English. Heck, even some cars were quite cutting edge for the day until the catastrophes hit real hard. Though the infrastructure was really bad.

Nothing really was drained for advanced projects, not even coffers. What happened was tragic mismanagement of agriculture, part manufacturing and building industry. This resulted in serious shortages all around and many deaths to famine.

Only at the end did innovation slow down, due to above factors and social unrest.