We are encountering problems with the "Log in to Community as User" button in our Partial Copy Sandbox. Instead of logging in as the user solely in that tab, this button now overrides any existing admin login, making it so attempting to visit any internal page will be done as that Customer Community Plus user.
Additionally, logging out as the Customer Community Plus user previously used to return to the user's contact page as the Admin user. Now, the system attempts to access the user's contact page while still remaining logged in as the user. It is now not possible to log out as the user without having to reload the Sandbox login page.
This was not an issue in our organization until last night. Even stranger, we refreshed the sandbox this morning and the problem has persisted, even though at no point was the error found in our production environment. This means that the error was present both before and after the refresh. We ended up moving some code into production yesterday, but it was code that had previously been written, just not fully tested. We also tried resetting the Apex and VF Page we moved into production into their previous iteration and that did not solve the problem.
Do anyone have any idea what could be going on here? It's possible that the code we pushed into production could be affecting our Sandbox, but it just seems strange that this same error is not being encountered in our production environment and that it was present both before and after the refresh. What could possibly be affecting the "Log in to Community as User" button?
EDIT*** This is now occurring in both our Sandbox and Production Environments.