Treading gently because I have use CD burners for safe keeping data rather than playable disks.
Have found that high speed burning often makes a disk which is only readable by the CD drive which burned it. Consequently I usually burn at about 4X in spite of the opportunity to go much higher.
This may be the result of a backlog of old "Jungle" disks which I bought a long time ago as a 100 pack.
Wise after the event I will go for a brand name without an impossible amount of logos and other stuff blocking the label and leaving little room for titles.
So back to your problem, It seems a tricky one, but if your old CDs will play on someone else's drive then you have an argument with Evesham which may be difficult to resolve.