I run an opnSense installation at home.
When i start an update, from CLI usually but from WEB is the same, often it get stuck downloading some packages like boost (but any might do) and either i need to stop it or wait for timeout and start again the update process.
Any way i can find out why this happens? It's very annoying but i can say that internet works fine (i usually login from remote location to do such updates) and the device itself is brand new, and seems to be working fine except this issue.
Here are a few ideas:
1. LTE/mobile connection is known to be flaky.
2. Some mirrors work better than others.
3. IPv6 can play tricks on you also.
Cheers,
Franco