For one thing, you may have missed something important in the owner's manuals,
especially that of the XU2600.
I don't have a chart of FRS/GMRS frequencies handy,
so I can't cross-check the two radios' channel numbers,
but you should double-check to be certain that,
regardless of the channel numbers indicated on the displays,
the two radios are set to the same frequency.
>You should know that any "channel number" can be applied to any frequency.
The two radios you have are made for different uses, and therefore
any channel/frequency combination in one may be altogether different
from any channel/frequency combination in the other.
Also, the 2600 has a feature the 9500 doesn't.
If that feature is activated, the 2600 may "ignore" signals from the 9500,
even if they are set to the same frequency.
Carefully checking all of the details should lead you to either
a resolution of the difficulty or the knowledge that these two
models cannot communicate with each other at all.