That's just because your base clock is probably set to auto and it's making it 99.25MHz or something, you could manually set it to 1 if you wanted and it shouldn't change anything other than giving you an even number lmao. Not like there'll be any performance gains, just if you're OCD about the number.
Also, based on what I've seen I'll throw in a vote for the B350 strix. Has better power phases than the Pro 4, but if you don't overclock to 4GHz+ then it won't matter. Some of the B350 boards, namely the Gigabyte ones, have problems with the VRMs overheating when you OC the bigger chips. In addition, am4 is going to be around getting new CPUs from AMD for at least 3 years, so I'd get a good board in case some faster but more power hungry chips get released soon.