All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
This has no effect on the validity of the prayer at all. The obligation in sending salutations upon the Prophet is to say: ‘Allahuma Salli ‘ala Muhammad’ only, and whatever exceeds this is desirable and not obligatory.
You have to avoid these whispers as being carried away with them leads to great evil.
For more benefit on the shortest form of Tashahhud and its different wordings, please refer to Fatawa 371557, 322516 and 375343.
Allah Knows best.