Water dispenser slow flow after filter change

I had the same problem when switching to Pur filters. There are two curved wedges inside the end that hold the filter away from its connection. It turned out that they were just a little to short, putting the end of the filter to close to the connection, and that's all it took to restrict the water flow. I went to the hardware store and found a thin plastic washer that would add some space (it was for a faucet diverter of some kind, thinner than a dime). It added just enough space for good water flow. Another benefit was it helped stop the icemaker line from freezing. A simpler solution might be to make sure to get factory-original filters.

When you change your water filter you must purge the line to remove any air or it will continue to flow all over the floor use as large a container as possible it will require you to draw at least 2 gallons of water to purge air in line. Your inlet valve is the reason your water flow is slow it is clogged with sediment from your water supply it needs to be replaced.