After playing two days without stuttering the problem got back this morning.
So i activated the ingame fps overlay and the fps overlay from origin.
The origin overlay always showed high fps (about 80 fps on Yavin map).
The ingame fps overlay showed always the same numbers for gpu,
but when the stuttering appears, cpu dropped to a red 49 fps for some frames.
Had this stuttering only in multiplayer matches, never in arcade oder campaign.
Had a similar problem in Destiny 2.
There was a bug in the clan list causing the image to stutter while retrieving online clan members.
Only solution there was to leave the clan. Don't know if the bug was fixed there - stopped playing it for BF2 ;o)
Perhaps this stutting in BF2 is also caused by some net code because it only appears in multiplayer matches and only sometimes (on some servers perhaps?)...