Samsung side by side refrigerator with ice/water dispenser in door.
Probably about five years old.

The water has always come out fairly fast. A few weeks ago it suddenly
slowed down. If the original flow was a 10 then now it is like a 6 or
7. I changed the water filter and at first it was fast then slowed
down again. I have purchased some new filters from a different
manufacturer.

What else can I check or do if the new filter doesn't help?