Hello,
Make sure your scaling is set to the right value.
However, if you're not happy with your taskbar size, a modification in the registry may help you.
Press Windows + R and type "regedit"
Navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
Right click, select new, DWORD (32-bit) value.
Name it "TaskbarSi".
Double click on it and set the value to:
0 - small taskbar
1 - normal taskbar
2 - large taskbar
After that, close regedit and make sure to restart your computer.
Hope it helps!
Cheers