Save and Open a bit buggy with language extension

Just open Micro and write some code and then save the file with the correct language extension. Then try to save the same file with another extension the syntax highlight will keep the previous language as reference. As shown in the screen:

Then if open another file with another extension whatever it is, after that open again the new file (the one with the different extension from the first) then it will load correctly.
This doesn't happen always and i still didn't figure out what could cause it.
For any further info i will reply as fast i can, i really enjoy Micro it is my first only keyboard Code Editor and i find myself really comfortable with it, especially for it being so lightweight.

Another small thing is normal that c# has syntax highlight like this?

With only the first bracket highlighted? Just asking.

Micro 1.4.1
Commit Hash: 1856891
OS: Windows 10 Build 17134.254

i7 4790k
16gb ddr3 1600mhz
r9 270x Toxic
Maximus VII Ranger

Start by reproducing the save-and-open sequence in Micro 1.4.1 on Windows 10: save code with one language extension, save it again with another, and reopen files with different extensions. Compare the syntax-highlighting state after each step, including the C# example. Done means the language consistently follows the current file extension and the C# highlighting behavior is understood or separately documented.