Drum seems to be out of balance and vibrates when in spin cycle

Hi from retired Englishman in SW France,

It is necessary to ensure absolutely that the machine has all 4 feet very firmly on the floor, and I mean firmly ;-0)
Doesn't matter whether it is empty or not but switch it off then-
very firmly push one front corner diagonally into the centre of the machine and see if the machine moves or rocks AT ALL, even the slightest. If it does you will need the open-ended spanner which came with the (new) machine........which of course went missing a long time ago?!! An adjustable spanner will suffice.
Adjust the foot under that corner downwards until it is very firmly- almost pushing- against the floor but not so far that the corner lifts up!
If this corner did not rock do the same to the other.
Once you cannot rock the machine the slightest little bit, screw the locking nuts up tight to the underside of the machine so that they will not move. Ideally the rear feet should also be locked.

(If this has not cured the problem it is possible that the internal suspension is malfunctioning.)

If this has assisted you please consider a 4 thumbs up for the rating.
Thanks and good luck!
John C