bedrock users joining the server using floodgate/geyser cannot walk into gatewayblocks created with "/portal gatewayblock"

It's an issue with the fact the blocks are solid on bedrock edition. It's nothing to do with my plugin.

Because they are solid on bedrock they can never enter the activation zone. You'll need to set an air portal surrounding it or something similar.

I may try to think of some ways around this more reliably but realistically you will need to find a workaround for the bedrock users or not use gateway blocks.

As we only check the current block and not surrounding blocks it's not a simple fix as well as any fix would make Java edition portals overly sensitive as well as a tonne of extra checks.