Do you have a Schenghen Visa from the Austrian Embassy?

I suggest that if Philippine immigration has stated they require an authenticated letter of invitation then you'd better have your partner get one.
If the Philippine Embassy in Vienna say it's not needed they should put that in writing to present to immigration.

Have you contacted the Austrian Embassy in Manila?
Yes Sir, i had a Schengen Visa from the Austrian Embassy.. I have already the affidavit of support and consent from the philippine embassy in vienna and my husband told me that the affidavit of support is like an invitation since the content of it also says that he is inviting me to austria, his address, my address and he will shoulder all the expenses from house and everything.. No sir, i haven't contacted the austrian embassy in manila after i got my visum.. The last thing i have in mind is call again the immigration on monday and asked if do i need to have my invitation authenticated..