When striders pathfind anywhere, they will consider any block at or below lava level that don't have another block below as LAVA (according to the pathfinding debug menu). If the block has another block below, it will be considered as WALKABLE regularly.

Not sure if this is an issue, since they can still pathfind directly to WALKABLE blocks, but (I think) this may make them stay more time outside of lava (I've found multiple staying on top of bridges since I built them).

Of course, enabling the pathfinding debug menu required me to slightly modify the game, but nothing that would make them change behaviour (I think).