Lava on Underwater Ruined Portal not turn into Obsidian

There a lava that not turn into obsidian even in water

 

Steps to Reproduce:
1. Find a Ruined Portal (you can use /locate)
2. If you found a Ruined Portal Underwater, You can see the awkwardness

Observed Results:
The lava not turn into obsidian

Expected Results:
The lava must be turn into obsidian, whatever it takes