I've been using the arrows at the right of the track panes for years without issue to expand and compress the heights of tracks I was working on.
 
But in the middle of mixing a song it all went wrong. The arrow now makes virtuially no difference in height. (like from 10 to 11 mm)
Searching this forum, Cakewalk Documentation and the interweb for info on how to change it back only led to endless rabbit holes of irrelevant info.  I can use an earlier saved version of the project where it still works but I'd lose about an hour of work.
 
Please tell me how this is done. Thanks in advance.

Are all of your tracks resisting resizing, or is it just one or a few tracks?  There's a way you can lock the height of a track, seems weird if they all somehow got locked.  If you right click on the track (on the small track icon near the track name), you can check and see if the "lock height" option (near the bottom of the list) is checked.  I always resize track height by hovering at the bottom of the track I want to resize in the track pane, getting the resize icon (like an equals-sign with an arrow sticking up and an arrow sticking down) and dragging up and down to get the height i want.  It seems like you can still resize this way even if you've checked the "lock height" option.

I think I know what you mean and this is how I "reset" my preferred view maybe someone else has a better way?
 
1. Shift click the Zoom Out Vertical (-) at bottom right corner to minimize all
2. Click the Zoom In Vertical (+) at bottom right corner x amount of times until you have track height where you want it (I do 12)
3. Repeat step 1 to minimize all and have them open as you would like with the arrows
 

Can't you just drag the track size with your mouse? Or am I missing something here?

Thanks, rcklln, I've always seen that in tutorial videos, but never known how to do that.  I usually just drag out each track as I need it, which is probably inefficient.
 
 
 

synkrotron
Can't you just drag the track size with your mouse? Or am I missing something here?

That takes forever if you have a lot of tracks to view, compared with just clicking on the arrows.

rcklln
I think I know what you mean and this is how I "reset" my preferred view maybe someone else has a better way?
 
1. Shift click the Zoom Out Vertical (-) at bottom right corner to minimize all
2. Click the Zoom In Vertical (+) at bottom right corner x amount of times until you have track height where you want it (I do 12)
3. Repeat step 1 to minimize all and have them open as you would like with the arrows
 

There must be something missing to your explanation or I'm reading it wrong. I repeat step one to minimize all and the problem isn't solved. They're all just minimized again.

If you have a track maximized and then drag-minimize it, if you click the arrows that will make it either minimized completely or maximized to the size it was drag-minimized to.
Drag the track to the size you want it and then the arrows should work to enlarge or shrink the track.
 

MrDoc
Thanks, rcklln, I've always seen that in tutorial videos, but never known how to do that.  I usually just drag out each track as I need it, which is probably inefficient.

Glad I could help - resizing each track individually can be a real drag (sorry couldn't help it ;)). Can also select all tracks, hold shift, then drag which will resize all tracks simultaneously.

jonnewyork

rcklln
I think I know what you mean and this is how I "reset" my preferred view maybe someone else has a better way?
 
1. Shift click the Zoom Out Vertical (-) at bottom right corner to minimize all
2. Click the Zoom In Vertical (+) at bottom right corner x amount of times until you have track height where you want it (I do 12)
3. Repeat step 1 to minimize all and have them open as you would like with the arrows
 

There must be something missing to your explanation or I'm reading it wrong. I repeat step one to minimize all and the problem isn't solved. They're all just minimized again.

The way I work is to have all track folders and tracks minimized and expand only the one(s) I am working on. I use the arrows to pop them open and closed as needed. Sometimes when I click an arrow to pop open a track, it barely changes it's size like you described in your OP. That is probably due to some previous zoom action I did.
 
To get the tracks back to a consistent size I'll do what I outlined and that should get you back to where you can expand and compress the heights of tracks you are working on using the arrows.