I think this was an issue back in 2023 already where X50s didn't play nicely with Zscaler. This issue appears to have come back with the new Firmware. Admittedly, I'm not sure if 1.5.5 or V1.6.1. I upgraded from V1.4.1. 

Zscaler shows that packet data is being sent and received. However, certain resources are not accessible. Primarly MS Teams, and certain websites fail to load. Using traceroute, I saw a lot of timeouts in between hops as well. Though other sites such as DuckDuckGo did not have issues with loading.

I initially thought that it was a DNS issue, but after resetting everything to 8.8.8.8, that didn't seem to fix it. 

I had to use the HTTP uboot firmware recovery steps to rollback to v1.2.2 and then upgrade back up to V1.4.1 to fix the issue. 

Wondering if anyone else has had similar issues and can recommend a workaround that allows me to upgrade to the latest firmware?