I know there is somebody who knows!

 

It appears that the crown might have been dislodged. Try screwing it back in , then open the case back, press the stud or screw near the crown stem. Pull the crown- stem out. Hopefully , this may resolve your problem. No harm giving it a try. Now, make sure the crown is now tightened. Reinsert the crown -stem back once again, pressing the stud button or the little screw as located before. Good luck.

 

The 6309-7290 is having a 2 pcs stem.
Its quite obvious that the male stem has came loose from the crown ; and hopefully its thread did not broken inside the crown.

You have 2 option,
A) have it fix by a watchsmith.
b) DIY

To do it yourself :
-first you needs remove the back case.
-than find the indent hole and push to remove the stem (see below video)
-use a tweeter to pull out the stem.
-dismantle both the stem and reinstall the male part to the crown (assuming the threads are not broken).
-reinstall in reverse. DONE !

-Hope it helps.

*That's not me in the video.

 

6309A stem is terribly design. Such design is inviting problem with such weak structure. Seiko is disappointing.