Vocal track plugin not working

[nutleysh]

Probably an old problem, but I'm new to Jamkazam, so apologies in advance if so. I cannot get a reverb plugin to work on my vocal track. I'm using a Macbook Pro and have downloaded several different plugins. They appear in the list of plugins (along with two Apple reverb plugins), but none add any reverb to the track. I've gone into settings and tried to make adjustments but this doesn't help. Thanks!