The 7D Mark II has seven different user selectable focus "patterns"...
1. Single Point Precision/user selectable
2. Single Point/user selectable***
3. 4-Point Expansion/main point user selectable
4. 8-point Expansion/main point user selectable
5. Zone/area user selectable, then auto selection
6. Large Zone/area user selectable, then auto selection
7. All Points/auto selection***
*** These two "patterns" have been standard on all Canon SLRs and DSLRs for decades. Some of the other patterns are available in other Canon camera models.
Go into the menu, navigate to the 4th page under the magenta "AF" tab, scroll down to the third item there "Select AF area selec. mode" and press the "set" button (in the middle of the back dial). You will see all seven of the AF patterns listed. Be sure any you want to use have a check mark above them. Unchecked patterns will not be accessible when using the camera. You can enable as many or as few of the patterns as you wish. Once you've made your selection, navigate to "Okay" and press "set" again to save your selection.
To change the selected patter, toggle through the options using the little collar around the AF joystick.
To move around either Single Point or the main point of either Expansion Mode or the Zone you can either use the joystick (if it's enabled) or rotate the main dial and back dial.
The AF system must be activated either to change the pattern or to move that AF point(s) around.
For a quick check, you can force the camera into the #7 pattern by switching the mode dial on the top, left shoulder of the camera to the full "Auto". (Edit: I just double checked this and found that, yes, in fact the active AF points do display in the viewfinder. I never use the full "Auto" mode and the first time I tried it I didn't see any displaying... but then discovered I'd accidentally switched my lens to manual focus! D'oh!
).
There are various other settings effecting AF that can be changed on the 2nd, 3rd, 4th and 5th paged under the magenta "AF" tab.
I don't know if they still offer it in the support section on the Canon website, but when I got my 7DIIs they came with a highly abridged (~150 page) printed manual, so I downloaded the complete manual (~500 pages) AND the supplementary autofocus-specific manual (~50 pages). The latter especially was very useful understanding all the different ways of tweaking the 7DII AF system. After using the cameras for four or more years, I have favorite settings for different shooting situations. (I don't use Canon's "Cases". I make all my own settings instead.)
I hope this helps!
P.S. Just though of a few other things...
1. It is possible to set up your joystick so that when you press/click it the AF will always return to a particular AF point. I've got mine set to return to the center point, for example. This is in addition to moving the AF point(s) around by tilting the joystick various directions. Have you set this up? If so, is it the point you seem to be stuck on?
2. The 7DII has option to set different AF patterns and point selections depending upon the camera orientation. In other words, when this is enabled you can set up one method and positioning of AF when using the camera in landscape orientation and completely different set up that the camera will switch to when it's held in portrait orientation. Honestly, I have my cameras set to NOT do this.... to instead use the same selection in both orientations. I experimented with this in the past on other camera, found it caused a little delay and sometimes messed me up. I have never used it at all on my 7DIIs, so maybe it works better or I could get used to it, but I've just never felt the need to try it again.
3. Do you have a battery grip on the camera? The reason I ask is because that has a secondary AF joystick and switch to toggle through the seven AF patterns noted above. If you have a grip fitted, maybe that's where there's a fault. You might try the camera without it. I use the Canon OEM grips on my cameras and they work fine (only problem I've ever had was accidentally turning them off at the switch on the right). I haven't used the cheaper 3rd party grips, but have heard of some occasional glitches with them on various cameras.