Thanks guys. @Toner, checked COS. Only 2 classes in effect. Standard COS64 for 101 and COS1 for all others.
@C5Z, I'm trying to post a pic of the "Flexibel Button" graphic here to show that there are no conflicting DSS buttons assigned. No matter what I do, when i open Extension 108, I can only exit by pressing "Cancel". All attempts to "Apply" the new programming cause a E000404 error.

Attached Images
230512 Ext101_Flex.jpg