Top level menu item name disappears when expanded.

My website's top level menu items are all system links.
On my mobile menu, if you click the + to expand a top menu item, the top menu item name disappears and there's no option to close up that menu.
I believe this is because the top menu items are system links. I've tried making the top level items a Menu Headings as well as a Separator but neither option seems to change that.
Is there some way to get this working like it would if those top menu items were linked to content?

Two screenshots attached to give you a visual.

Hi
Please give me the url of the page so that I can check
CEd

Sorry about that, I thought I provided that in the private message section.

j4upgrade.oaca.info/

ok, it seems that you have setup a font size on the opened state at "0.4px"
this is very small
please remove that and tell me

Okay yes I had noticed that. Had tried changing one instance of that super small font size with no effect, but then today I noticed there was another rule with a font size of .4. Changing that one solved the problem.

I looked through the style settings for the mobile menu but was not able to find that a font size of .4 had been assigned anywhere. For now I have created 2 style rules in my custom.css file to set that font size to 14px and that resolved the problem. Do you have any tips on where I might find that setting within the mobile menu style settings?

check in Mobile Menu >> Level 1 Items >> there is a text options area