Empty Server response sometimes in in Chrome

I have a strange issue on a website for a customer. He is hosting via GoDaddy.

Some context:
It is a custom WordPress site fetching content via Ajax to load into the page.

Problem statement:
When testing, I noticed some random occurrences for empty responses coming back from the server. Triggering the same request over and over, it happens that the response header is empty. This is strange as I had performed the same test seconds / minutes before.

This is the result of a successful response:

{"finishTitle":"Bourland 2","finishNumber":"VP2","highlightImage":"https://qdr.app/wp-content/uploads/2024/08/leathershandtas6-320x202-1.jpg","galleryImages":"<img src="https://qdr.app/wp-content/uploads/2024/08/leathershandtas6-320x202-1-150x150.jpg" class="selectedFinishImage" data-large-src="https://qdr.app/wp-content/uploads/2024/08/leathershandtas6-320x202-1.jpg" alt="" /><img src="https://qdr.app/wp-content/uploads/2024/08/leathershandtas3-320x202-1-150x150.jpg" data-large-src="https://qdr.app/wp-content/uploads/2024/08/leathershandtas3-320x202-1.jpg" alt="" /><img src="https://qdr.app/wp-content/uploads/2024/06/8CCL-Basement-Office-Doors-Looking-at-Egress-150x150.jpg" data-large-src="https://qdr.app/wp-content/uploads/2024/06/8CCL-Basement-Office-Doors-Looking-at-Egress-1024x681.jpg" alt="" /><img src="https://qdr.app/wp-content/uploads/2024/08/leathershandtas5-320x202-1-150x150.jpg" data-large-src="https://qdr.app/wp-content/uploads/2024/08/leathershandtas5-320x202-1.jpg" alt="" />"}

With a response header looking like this:
response header successful response

Result from an empty response:

The response itself is empty.

We have the following response headers. You can see the difference.

response header empty response

What could cause this and how can it be solved?