1997 Chevy Blazer rear drum brakes grabbing/skid

I am seeking some advice on an issue I am having with my 1997 Chevy Blazer 2-door 4X4 with the 4.3L V6 engine. The issue I have been having is the rear drum brakes start to grab and sometimes lock the rear wheels up at slower speeds when trying to brake. I first noticed the problem about a year ago. I discovered that my rear axil oil seals where leaking on the rear passenger side. The oil was contaminating the brake shoes and causing a squeal noise and the rear right wheel to grab and lock up when trying to stop at a slower speed. Shortly after my discovery of the leaking rear seal I replaced both sides and replaced the rear differential cover and gasket. I refilled the gear oil with Locus 75-90W. Next I cleaned up the rear brakes with brake cleaner to remove all the gear oil contamination, installed new brake shoes, both wheel cylinders and adjusted the brakes properly. I also adjusted the e-brake cable to make sure it was catching when it should be and not creating a drag on the shoes. I grinded smooth the wear grooves that developed in the backing plate and applied a small amount of anti-seize to where the shoes meet the backing plate. I checked all the hardware and the self-adjusters and all seemed fine. In addition I ended up replacing the ¼” brake line coming back from the ABS module to the center hose. I also had to replace the two 3/16” brake lines going across the axil from the center hose going to the new wheel cylinders. When trying to bleed the new wheel cylinders I blew out the ¼” line near the front because all the lines where badly rusted. I bled the rear brakes with the help of a friend and got all the air out of the system. I also installed two new brake drums. The brake drums are the Pro-Stop brand from Pep Boys and the brake shoes are also the better line of the Pro-Stop brand and are organic material.
The issue with the brakes grabbing seamed to go away for a long while and has returned again. The rear wheels seem to be doing too much stopping and grab when I apply the brakes at slower speeds or coming to a stop. The rear right wheel is worse and skids but, the rear driver side just feels grabby. If I remove both drums and clean the dust out and manually adjust them closer to the drum again the issue goes away for about two days of driving and starts back up again. It was happening mostly when hot but I found that it is really bad when I first start out after the vehicle has completely cooled off for a few hours. When I attempt to stop at the end of the driveway the rear brakes grab, the passenger side skids and I get a horrible metal grinding screech noise from the drums. I am seriously running out of ideas. Why does cleaning the brakes make it stop for a couple days and why does it build up so much dust so quickly. They don’t feel like they are dragging, hanging up or getting over heated. I have spoken to tons of people and I have gotten a different answer from everyone. The only thing that I didn’t replace is the single rear center hydraulic brake hose that connects the ¼” single brake line on the frame to the crossing two 3/16” brake lines on the axil. Is it possible that hose is collapsed internally from age and causing the rear brakes to act up? Why does only the passenger side skid and not the driver side? Another person told me to get rid of the crappy Pep Boys shoes and go with OEM shoes. I feel like all I am doing is throwing time and money to this issue and not getting anywhere! I know it may be hard to diagnose this issue without looking at it but, I feel like there has to be someone out there that has resolved this problem. I read tones of posts online about many different GM’s having the same problem and many of the responses are the same I am getting and the suggestions don’t work. I have ordered a new center hydraulic brake hose on Rock Auto and I got a new spring and hardware kit that I am going to throw on when it gets warm again. I invite any insight and advice that anyone can offer. I am getting desperate. Thanks in advance for any suggestions. P.S. The brake shoes are installed properly. The bigger shoes are connected to the e-brake cable and facing the back of the vehicle. Thanks!