Resetting glass porthole in Miele W460?

I have a Miele W460 washing machine about 15 years old.
Mod: W460S Nr. 10/67777394 Type: HW04-1 CEIPX4
I noticed that the porthole glass has slipped round by about 50⁰. There's no sign of leaking, but the glass is quite scratched.
I think I just need to slacken the hex screw by the hinge and move it back.
Are there any problems I should know about? Was any jointing compound used? How likely is it that I'll make it leak?
Is doing nothing an option?