Corruption of TLC plates or solvent

I have been conducting TLC experiments, and sometimes I observed some lines when I use mixture of eluents.


[![TLC line1](https://i.stack.imgur.com/OlAbT.jpg)](https://i.stack.imgur.com/OlAbT.jpg)


And I found that some lines are observed after I develop the TLC plates with some eluents. And these lines are detectable via both 254 nm and 365 nm UV.


[![TLC line2](https://i.stack.imgur.com/rZpwf.jpg)](https://i.stack.imgur.com/rZpwf.jpg)


The plates might be corrupted when I cut it, so I test a small piece of unused plate. In this time I didn't develop the plate, rather immersed it quickly. Then the borderline was detected by UV. Even, the borderline turned yellow after it is immersed in methanol or ethyl acetate.


[![TLC line3](https://i.stack.imgur.com/b3EFx.jpg)](https://i.stack.imgur.com/b3EFx.jpg)


Are the plates corrupted due to long-term storage? These plates existed before I joined the lab, probably stored more than 2 years. I test the unopened solvents although they are stored for some periods after purchase.


