While your Aussizz' oral-fluency score matches the PTE's points, the difference we see here between our score and the PTE's score is pretty unlikely. It is difficult to have one solid reason for that.
But, you have scored very less in pronunciation which means that either the words in the original PTE test were tricky (that we often see) or it seems that you compromised on pronuciation for the sake of having better points in fluency.
We recommend you to go for 'speech to text' software by Google (available online) and start recording your voice on the software. Check whether Google's software catches every single word you pronounce.
Learn pronuciation from authentic dictionaries like Longman, Collins, Oxford, and Merriam Webster. Search and click on the pronunciation for the word of yours that Google could not identify.
Hope this helps.