Helpful if you said what plot of server, Creative, KitPVP (If you bought it) Imprisoned, etc. Anyways I experienced it too, if you can't get to your plot, meaning that you are in a void of nowhere and when you do f5 you can't even see your own minecraft body, then say in chat you need help from a staff, or /tell them on a different server if it forbids you from typing due to lag or chunk strangeness (Might have been fixed), and see if they could tp you right there with /tp (Mod's Name) (Your username), or have some guy who can tp to you /setwarp (Something), and then he tells you the warp and you /warp (Name of warp), then you are at plot, and just in case /sethome or /setwarp (Something) for yourself in case it happens again. I did that for myself just incase. I hope this helps you in case you are still having trouble. If still something's wrong, check your internet bars and provider and your MC Version is on 1.8 and see what's causing it, maybe computer is lagging due to memory or because it's on render distance 16 Fancy Mode and everything Fancy, it causes some memory lag occasionally and may glitch the plot. If you are still having trouble then please say under this (Thank you for the idea, but it didn't work) or something similar. If you found this useful to any problems you have with creative plot, please press Agree, if you found this useless to your problem with Creative plot lag press Disagree.
~Royal