Resize to 1023 rounds up to 1024

Hi everyone,
I have a deliverable of 1023x542. However, when I resize to 1023 it jumps up to 1024. I’ve heard of this issue before, the number not being divisible by 4, but can anyone explain what’s actually happening and why?
Thanks!

I have been looking into the problem with 8-bit files
Export resolutions in 8-bit

But in some cases Flame just seems to round up. Not sure if this is due to 8-bit limits or just trying to prevent bad numbers later on.