Issues with printing small lettering (Prusa i3 Mk3s)

[ats101]

Howdy,I am new to 3d printing and I cannot wait to explore it further. I am using the above printer using all standard components (0.4mm nozzle). I have been printing a few bits and bobs which has lettering on them but cannot seem to get an up to standard finish. I am using PrusaSlicer as the software. Even in the slicer, there is gaps in the letter where I expect there to be infil but there isn't. I have tried playing with infil, detect thin wall, etc. The letters are about 1x1cm so not exactly tiny. I have tried varying layer heights also. Have a look below. Any settings for printing lettering to get a crisp finish? Would a smaller nozzle help?