1989 300Se drive shaft /flex disc slack?

[unkl300d]

Hello ,
My searching the archives did not come up with the answer.
Is it normal for the drive shaft to be able to be 'turned' a bit with car engine off and parked on ground ?

I notice that the shaft has a bit of slack at the front flex disc only where the drive shaft connects to the disc. Not where the disc connects to the tranny.
The disc looks OK visually. The bolts seem tight But the drive shaft bolts that connect to the front disc do have a bit of side to side slack within the disc holes. Normal or should they be tight and allowing no movement?

Car has about 136K miles. I'm sure the flex disc has been changed at some point in time before.
Otherwise there is no vibration while the car rides or clunking noise.

What alerted me was a flapping noise periodically when it was put in gear. The noise sounded like plastic paper slapping rotationally but faster than the slow driveline.
That's why I got under to inspect.

Both flex discs look visually OK except for the drive shaft
'slack'. Its about a 1/4 inch or a bit less rotational slack.

Thanks.