Problem while linking third-party library

Hello! I am creating a small .a lib file containing a bit of c++ code in my plugin that I want to remain hidden.
I have built it using the 64bit version of g++.exe and ar.exe provided by WinBuilds, and for now the source code of this static library looks like this:

void LogicTick() { }
void StopLogic() { }

Now the problem is that after adding this library to my Build.cs file using this line:

PublicAdditionalLibraries.Add(Path.Combine(ModuleDirectory, "ThirdParty", "LBLogic", "libLBLogic.a"));

The Unreal Engine Build Tool undeniably finds my lib file, (it doesn’t tell me otherwise, and whenever I give it an incorrect path, it tells me it’s not found, therefore my lib file is found)
but the functions declared inside it are not found.

Visual Studio gives me this error:
“2 unresolved externals”
“unresolved external symbol “void __cdecl LogicTick(void)” (?LogicTick@@YAXXZ)”
same for the other function

In the cpp file where I try to use these functions, I include the prototypes of the two functions:

void LogicTick();
void StopLogic();

And then call them, but they are just not found.
When I try to call them in a normal program by linking them through the command line like so:
“g++ main.cpp -L “.” -lLBLogic -o test.exe”
Everything works perfectly fine, but not with Unreal Engine…

Has anyone encountered this problem or know a way to make it work? I am completely stuck and have searched the internet for days now but I have found no solution. Thank you very much