Hey, could you provide the crash logs either to me on Discord (see the plugin page for a link) or at
[email protected]? I am surprised that this is happening as spigot forks tend to just disable the plugin if it's having errors.
Given the nature of the issue you have described, I sadly can't see how Advanced Portals would be behind this, so if you could supply me with any information on why you believe it's my plugin or how to re-create this issue, it would be a massive help.