There are some speed bumps here… It may be more accurate to say we have hit desert road that is all pot holes.
The current freepbx version is freepbx 2.11. The module is not supported by freepbx but has been kept up by the community.
There has been hundreds of improvements, bug fixes and changes between where you are and current for freepbx and I imagine there has been many updates to that module alone. Your issue may stem from an issue solved in one of these changes. The best thing to do would be to pull you current then see if you are still having issues. I dont believe you can be both current and within the Elastix umbrella so you may have to jump off of elastix to find a resolution. As an alternative you may wish to work with their developers to see if they can back port any fuxes from current stuff in to their older versions. It may be faster to jump ship and upgrade platforms
I should have said more correctly the software is not maintained by the FreePBX team. It does have an active community.
That being said, you have a really old version. Certainly the filenames are case sensitive as is the file ownership.
You can install tftp client and test on command line to 127.0.0.1 loopback address.
The software you are running is very old, and the FreePBX version is end of life. If you are bent on staying on that platform you are putting obstacles in the way of success.
I Have found solution, when phone downloads XMLDefault.cfg then it switches to SPCP mode. I have just deleted this file from tftpboot folder and everything working perfectly.