vertical bar pulling away from horizontal base bar

SGD-R20-73x81 with the handle-containing vertical bar pulling away from the lower horizontal panel, that surrounds the glass. I tried screwing the 1 screw I found in the assembly tighter, and this lasted perhaps a week, and now has me wondering if that was actually the screw for adjusting the roller at the base? The screw seemed smooth at the end, which I took to mean stripped at the time, but now see there should be an adjustment screw. Perhaps the other screws have fallen out?
The door is about 20y old, so if it is time to replace it, so be it, but if it is a rlatively easy fix then I will order the parts to do so. Thanks!

Thanks. It is the bottom of the sliding glass door. The horizontal part that slides on the track is pulling away from the vertical strut that contains the handle above.
I wondered if there was a simple way to re-attach the 2 pieces per screw set, etc. It is looking like it is not feasible; likely the door needs to be replaced.