There can be several issues. Since you just installed the new bearings on the support bar you can see that they are rolling. 2. Remember that the rail levers need to be locked down on the front and back of the machine before using the sliding table. When you lock those levers down it will pull down on the rail a bit. 3. If you have the rail pulled out in front of the machine put in the support bar on the end the rail or it will droop some. 4. The next would be to check if the cross supports on the bottom of the table are not dragging on the rails or the sliding table is not rubbing the fixed table. Get a flashlight and look at it from both ends and from below while moving the table back and forth. Most likely you will feel where it starts to hit and just do a close visual inspection from every angle. 5. If you have cut some long or heavy pieces that have hung off the side of the sliding table that can bend the sliding table support bars that the bearings are mounted to. I have had to bend them back straight before. I hope this helps but if you still are having issue please feel free to contact me or contact the group at groups.io/g/roblandx31

Next to the great tips you've already had. There's two bolts visible on the outside edge of the sliding table where the sawtable and sliding table slide next to each other. These bolts compress the bearing assembly to take away side to side play. These are easy to overtighten and will introduce a LOT of friction very fast