Clonking noise from gearbox help please.

[BrettandSam]

Hello all,
I took the 944 out for a drive 5 miles at most and when I got back in the drive it was making a clavckerty clack noise from the gearbox while idling in neutral. Also a clonking noise from the back of the car when I put my foot on and off the clutch. I’ve videoed it and put it on youtube.
I would really appreciate some help in diagnosing the problem and the remedy.
https://youtu.be/Q6_qdhNh3Yo

Thank you in advance.
Brett and sam.

[Endoman]

I would drain the gearbox oil and check for any bits, there are 2 magnets inside the box but some stuff will drain out if a gear has lost a tooth. The plug is not magnetic but you can fish in there with a magnetic probe. make sure you can undo the filler plug first. The noise sounds more pronounced than normal gear lash which disappears when you press the clutch pedal.
Has any part of the transmission had work done on it recently including clutch?