Does it do that all the time or some of the time? One of the bugs in the newer Uniden scanners affects EDACS systems. What happens is when a patched talkgroup is active, it will switch to it immediately, ignoring any delay. Since there are usually one or two patches active at any one time, it happens frequently. If it always ignores the delay and goes to non-patched talkgroups, it is likely something else, but if it doesn't ignore the delay all the time, it's probably the bug.
Clayton