There's a reason why it's recommended that you stick with one kit, the size and speed you want.
Picture a dude on an assembly line, he sticks 4 sticks in the mobo. Doesn't work. He grabs another stick from the giant pile of ram and starts swapping sticks until he gets 4 that work. He might go through a hundred sticks before that happens.
You buy the kit, 4 sticks, bam, factory certified. Works like a champ.
Same dude at home orders a second 2stick kit from Amazon. Doesn't work, rma, wait 2 weeks for replacement. 11 months later he's still plugging away, Amazon is delaying shipments and rma because they are rightly upset, dude still doesn't have 2x compatible kits.
Buying a full kit, you pay for dude to do all the work matching and certifying the kit to guarantee it works. Mixing and matching, you are the dude at home still waiting and plugging away, never having gotten 2x compatible kits.
It's a Ryzen 3000 series. Sweet spot is 3600MHz. Ryzen also do not like 4 ram sticks and will fight compatability every which way it can. I'd strongly suggest yo purchase a 2x16Gb kit, and sell the 2x8Gb 3200MHz. The cost difference will be negligible compared to the subsequent argument that 4x sticks from 2 different kits could possibly entail.