After converting an existing blueprint to use powered rail entities, the new blueprint has issues where whenever there is a split in the rail, one of the splits isn't getting power. I converted the blueprint with an upgrade planner that took every rail piece and curve and upgraded it to the electric counterpart.

Photo: https://imgur.com/a/TUO7AgQ

I don't know why this would occur.

Nothing I need is handled in blueprints.

Only possible explanation I can think of is things were built on the exact same tick, but that also shouldn't cause this because each rail placed makes sure it's connected to any neighbours.

Does removing and replacing the first rail with no power after each split fix it?

Yes. If you delete the first rail after the split and replace it the power flows through until the next junction where it stops again. Replacing the next rail then lets it flow further down the chain.

I can try looking at it, but I don't know what I'd even be able to do to fix it