Hello Waterashes,
I'm extremely sorry about this inconvenience. If you are still stuck, please try the following solutions:
▪︎ Try Alt+Tab
▪︎ Use an Escape Rope
▪︎ Try battling another player and losing, this should bring you back to your last visited Pokecenter
▪︎ Try typing /ref into the chat bar, or clicking the refresh arrow on the bottom toolbar
▪︎ Log out, and then back in
▪︎ Close the whole client and start PRO again
Please let me know if you're still stuck after trying the given solutions. I'm looking forward to hearing from you in order to help you more. I hope you have a great day!