Welcome to the Community @DanLee.
How many signal bars are you receiving? Are you inside your house when you tested the speed or outside?
Are you getting 4G or 3G symbol on the signal bars?
What troubleshooting have you tried so far?
I am having the same issue and has been going on for a while now.
At my work place my friend has a good connection while mine appears sos. I am talking about place within city. Many times i can't even open web browser and even if it opens takes time to fully load.
I tried calling TPG and still not resolved. Same ** everytime I called, switch-off / reset and blah blah...
Whole family uses TPG but now thinking of changing to other provider.