Thanks for raising this to us, please post a screen shot of the speed test result on this thread using both testing site.
Also please confirm the troubleshooting you have done and to better understand the situation send us your account details (Username/Customer ID together with the address on file).
In the event that the affected devices are connected via WI-FI, we did an articles that you may find helpful this will help you improve the wireless connection at home, please see link below.
Let us know how it will go.
I am having a NBN Broadband 50 connection . The Speed test on the TPG app seems Fake as it’s showing my speed as 55 mbs currently, while speedtest.net show 1.23 mbs. Please look into this issue ASAP.