Issues making a library

I'm trying to convert a sketch to a library, but it seems th CPP file is not being included in the build.

The library is:

library/FAB_LED/FAB_LED.h
library/FAB_LED/FAB_LED.cpp

The example is:

library/FAB_LED/examples/FAB_3Bytes/FAB_3Bytes.ino

The error is:
"class::method() used but never defined"
When the example calls:
ws2812b_portD6.clear(numPixels);

In file included from FAB_3Bytes.ino:15:0:
C:\Users\dant\Documents\Arduino\libraries\FAB_LED/FAB_LED.h:114:21: warning: inline function 'static void avrBitbangLedStrip<high1, low1, high0, low0, minMsRefresh, portId, portPin>::clear(uint16_t) [with int high1 = 6; int low1 = 2; int high0 = 2; int low0 = 2; long unsigned int minMsRefresh = 20ul; avrLedStripPort portId = (avrLedStripPort)4u; unsigned char portPin = 6u; uint16_t = unsigned int]' used but never defined [enabled by default]
static inline void clear(const uint16_t numPixels);

Post the code of all 3 files in code tags.

I think the issue is with templating and defining properly the templated methods in the CPP file so it actually matches the hpp file definition. There's some magic there I have not quite figured out yet.

In particular my class is templated and some of its methods are templated too.