[SkyBlock] Nether Portals Appearing?

Your username:DavLew222

In which minigame/server does the bug occur:Sky Block

Detailed description of bug: When playing and Afk on my island random Nether portals just appear on weird and random parts of me and my friends island. when i was Afk my friend had logged off so it wasnt either of us doing it. we are both very confused and annoyed by this (our island coordinates are -7199.5, 116, 24192) We dont know what to do and have just been destroying them. is there a way to fix this problem or do we just have to deal with it.