Large .mat file (1x1 struct) showing as empty in workspace although it isn't

So I have a .mat file, and I don't see any variables present in the struct. I am at a loss to understand why this is, especially since the .mat file has a size of 2 GB, so I definitely know it isn't empty. I'm attaching a screenshot here. If anyone could help, I'd be most grateful!

[Stephen23]

What MATLAB version are you using?

[Zuha Yousuf]

Hi thanks for responding! It's R2018b

[Walter Roberson]

What shows up if you ask to see fieldnames() of the struct ?

[Zuha Yousuf]

Okay so this is what shows up! It's a 36 by 1 cell array.

[per isakson]

"How do I ask to see fieldnames?"

>> S.a=1;
>> fieldnames( S )
ans =
  1×1 cell array
    {'a'}
>> 

The variable editor says there are 36 fields

What does

whos S 

return

[Zuha Yousuf]

This is what it returns!

[per isakson]

Thus you have a scalar struct, rez, that is 4.5GB. And you know the names of the fields. Try

plot( rez.xc, rez.yc )  % it might produce a plot

Remains to understand why the Variable editor doesn't show the names of the fields.

[Walter Roberson]

I had a hypothesize that perhaps it was limited in the number of fields it would display, but I just tested with 50 and it had no problem with that, so that explanation does not work.

[Zuha Yousuf]

Yes, that's what I'm confused about :/ Like it's just not showing in the workspace

[per isakson]

"Like it's just not showing in the workspace" Fields of structures aren't shown in Workspace.

I assume that there is something perculiar with rez that suppresses the display of the field names in the Variable editor. However, I cannot guess what.