Just got a Line 6 DL4, and trying it out.

Seems like when when I press play/stop which is the on/off switch (someone correct me on this if this is wrong), and for example I set the delay time to a certain level, it doesn't register and goes to the default, so then i'll have to redo the actual setting. The same goes with the different models, i'll have to re adjust it manually, by hitting the play/stop, then adjusting it to whichever model I want to use.

Is this how its supposed to work?

I tried to find articles or posts on any of these problems I've been having, or maybe I'm just a noob trying to learn how to figure this out.. any help is appreciated. Thanks.
Larrivée D-03R
US Fender Telecaster, Vox AC15
you should read the manual, im sure you can download it from the line6 website if you don't have a copy.

Play/stop is for the looping mode to turn on and off the loop playback. If you want to mess with the delays then turn our first knob to the left to the delay sounds you want, and mess around with the controls, they all work differently depending on the delay model you're using. Also check your Mix knob to ensure you're mixing in the delay sound you want to the volume you want.

If you've found a delay sound that you want to keep, then you have three presents from the left to the right, the last button is for tap tempo. To save a preset click on one of the 3 switches to 'on' (red light on), then select the delay and select the desired settings. When you're happy with the present, step on the same lit button again and hold it for roughly 3 seconds. It will now save it on that button, now you can turn it on and off by selecting it. You can do the same to the other 2 buttons.

Hope that helps, have fun.

Gibson Les Paul Studio w/dirtyfingers pickups
Gibson Joan Jett Melody Maker
VOX ac30 head
Marshall 1960 4x12 cab
Fender Hot Rod Deville