Does zero padding change the actual frequency?

I tried adding zeros to the end of a 10 Hz signal, by making it the double the length of original signal length, I know the resolution should increase in fft , (but not more accurate). But as I noticed the frequency shifts a bit as well towards 9,5 Hz , even if i zero padd even more it will still shift but slightly, is that normal? how can I solve it? and is there a limit to the amount of zero padding needed? are there any drawbacks with zero padding?

[Image Analyst]

How many elements per second do you have along the time axis? Can you show your code?

Answer 1

[Azzi Abdelmalek]

When you add zeros to your signal you get a new different signal, obviously, its fft will be different