Table of contents incomplete in mobile version of Apple devices

Hey all! Hopefully this is the right category for my issue. So I created this ToC for my blog posts and I thought it was working out very well in every breakpoint, since I didn’t notice any problems with it on the browser window by just resizing it. But as soon as I opened the site from my iPhone, I noticed that some of the headings in the ToC are missing.

Currently, we have about 10 blog posts and I checked each of them: The first like 6 to 7 headings are always showing, while the following 5 to 6 headings are constantly missing. The last heading is also showing in every ToC. It seems like it doesn’t matter whether it’s H2 or H3 headings. I can see a pattern, but unfortunately I cannot figure out what the source of the problem is.

I could reproduce the issue on Safari and Chrome browser on several Apple devices, as you can see in the following screenshots.

For reference, this is the correct version I can see by resizing my browser window:

We also opened the site on a few Android phones and the ToC was completely showing - no issue at all. That’s when we realized it seems to be an iOS-based issue.

Any ideas on how to resolve this? Thanks!

Here is my site Read-Only: Webflow -