If you search you will find many similar problems
The most likely issues are tarnished contacts or debris in the port.
There is also the possibility that the modules contacts to the core module are not efficient.
The port may also have suffered physical distortion after many plugins especially if it has been wiggled around to get it to work, also even many cables can be a failing point.
Best check for debris first.
If you are out of warranty you can remove the bottom module and dismantle it for a better access to cleaning.