I have an ‘16 is350 awd and when i drive on manual mode sometimes when i try to upshift or downshift it doesnt do it. It only has 80k kms on it.

 

It's possible the ECU is not allowing the shifts for a particular reason.
If there was an actual malfunction you would like have a check engine light on.

Maybe the conditions to which you are trying to shift it are outside of the parameters that the ECU will allow the shift.
For example, if you're going too fast and try to downshift it won't allow it, like doing 110kmph and trying to downshift from 4th to 3rd.
Or if the engine is cold and trying to upshift to the highest gear...it may not allow that either.

Maybe you can provide some detail and to when the upshift and downshift don't occur.

 

There is an audible beep on my 2016 200t when the ECU rejects a shift (typically at higher speeds and/or when cold as Sasnuke mentioned).

 

Yes...I forgot about the "i don't think so" beep to let you know the requested shift isn't going to happen.

 

it happens when im flooring it and try to upshift to the next gear it stays in the same gear but when i try to upshift again it does it.

 

Is there a specific speed this happens?
Is there a specific gear it only happens in?
I'm assuming you don't hear any beeping when you hit the upshift...are you using the paddle or shifter to upshift?

 

The car sometimes shifts funny if you leave it in Auto and try and use paddles...if you are in actual manual mode and it does that I’ve never heard of that before.