If a shop is doing the trans oil and filter, I,d get them to check the shift linkage and possible motor or trans mounts. Maybe there's something simple not letting it enguage in drive sometimes. My 93 2.3 shifts late like yours when cold and is normal. At 155,000 miles my trans fluid has always come out looking brand new and at 120,000 miles when I pulled the pan off it was spotless. At this point I would not add a bottle of " trans fix in a can". Just go with a oil and filter change.