smart modem 4G apps not working

[hylands]

Hi - my smart modem is on 4G backup as the NBN is down. Some apps on my Galaxy tablet are not working even though it is connected to the modem on wifi. Web browsing works but email currently is not syncing. Some other apps say there is no network connection. Same issue on my Galaxy S7 - some apps work others do not and I have to turn off wifi and use data for them to work..

Any ideas?

[cf4 · Accepted solution]

This is probably due to there only being a IPv6 address on the WAN in 4G backup mode. The modem's PDP type can be changed from IPv6 to IPv4v6 so that the modem will receive both a IPv4 and IPv6 address. See last part of section 26 of document linked in this post for how to change PDP type.

Telstra Smart Modem Gen 2 Technicolor DJA0231
https://crowdsupport.telstra.com.au/t5/Modems-Hardware/Telstra-Smartmodem-Gen-2-Technicolor-version-...

Telstra Smart Modem Gen 2 LH1000
https://crowdsupport.telstra.com.au/t5/Modems-Hardware/Telstra-Smart-Modem-Gen-2-Arcadyan-version-LH...

[hylands]

This worked - thanks. Fortunately I knew that I had the Arcadyan version of the modem. Note that the section in the Arcadyan manual is 25 (not 26) "4G Cellular Backup".

Great resource.