Other players are reporting the same, so Hearts of Iron 4 is at the moment fully complaint free! In our tests that we ran for about 6 hours, there weren't any desyncs experienced. patch, which has addressed the issue of desyncs.
UPDATE: Paradox Interactive has released the Beta 1.5.2. We aren't able to get any games going without them happening right from the start and throughout the game. UPDATE #2: We sadly need to report that the latest Beta 1.5.2.