When lava is placed on top of a block, walking directly under the block will change the screen to the "underwater lava" texture as if you were swimming in the lava itself. I added an example picture of what the setup looks like. This is just a minor texture glitch, but I figured I would report it as it can cause some complications. Have a good day 🙂
Duplicate of MC-47520 - If you have not, please use the search function in the future, to see if your bug has already been submitted. If you could not find the original report, please comment with the keywords you searched for.