MacBook fails to load certain websites via iPhone Personal Hotspot

Certain websites and services fail to load on my MacBook when using iPhone Personal Hotspot (ERR_CONNECTION_RESET / ERR_CONNECTION_CLOSED)

I'm experiencing a strange networking issue when connecting my MacBook to the internet through my iPhone's Personal Hotspot.

Some websites and web services work perfectly fine, while others intermittently fail to load or return network errors.

Symptoms:

• Certain websites and services fail to load.
• Chrome Developer Tools shows errors such as:
  • net::ERR_CONNECTION_RESET
  • net::ERR_CONNECTION_CLOSED
• Some API requests fail repeatedly with 0.0 kB transferred, while other API requests succeed with HTTP 200.
• The affected websites sometimes display a "Failed to fetch" error.
• The same websites and services work normally on my iPhone.

My network setup:

• Device: MacBook
• Internet connection: iPhone Personal Hotspot
• Browser: Google Chrome
• Connection type: Wi-Fi through Personal Hotspot

This makes me suspect that the issue might be related to how the MacBook handles certain network connections through the iPhone hotspot, rather than the websites themselves.

What I've tried / would like to investigate:

1. Could this be related to DNS resolution, IPv6, MTU, or TCP connection handling?
2. Could iOS Personal Hotspot or the mobile carrier be resetting certain connections?
3. Are there any macOS network settings that could cause this behaviour?
4. Is there a way to diagnose whether the issue is occurring at the DNS, TCP, TLS, or HTTP level?

Has anyone experienced something similar when using an iPhone as a hotspot for a Mac?

I'd appreciate any suggestions for diagnosing and resolving this issue.

I've attached screenshots showing the network errors and failed API requests.

Thank you!