The lcd ribbon bonds sensitive especially to pulling, strain, tearing.
The adhesive can fail in may ways, poor handling or cleaning using solvents can run down into the bezel and contacts. Age, heat and model defects can also be a source of the issue.
Generally pressing on the contact bonds lightly to see if a pressure bodge can be applied is lower risk than the disassembly and poor handling during so itself.
Commercially bonds can be redone, but its labor intensive and requires expensive equipment.