Is the system you are monitoring motorola or edacs, gotta have this set right.
If edacs, gotta enter the frequencies in a specific order.
Did you enter the frequencies while in trunk mode? if not, things will work kinda like
you describe. (Had this problem myself on a Uniden model, you think you are in trunk mode and ......well, you're not).
Address these 3 and you should be successful.
Once the above are in correctly, just hit Search while trunking the bank to
make sure you get hits and the talkgroup info displays. If a frequency displays
you aren't setup right.