[GAMEPLAY] In Nexus Blitz, the nexus regens to full hp after entering then exiting the fountain

Just encountered this bug in nexus blitz (see the gfycat clip for reference).

What happened:

-Our poppy ults the enemy nexus into their fountain -The nexus starts regening its health -Even after it leaves the fountain the nexus keeps regening its health until it hits full hp

If it had stopped regening when it left the fountain it would have made sense to me, but it continued even after it was out of it leading me to believe theres something fishy going on here.