(ASP MVC) Glyphicons Bootstrap does not work in Firefox

Question

I have an ASP MVC 5 application where I use the Bootstrap that comes along, however, both in debug and in publishing, the Bootstrap icons (glyphicons) are not being loaded, see image:

I am using the version of Bootstrap v3.3.7 in the project Bundle.

In all other browsers, it works perfectly, only in Firefox that doesn’t work.

I thank anyone who can help.

EDIT 1:

Inspecting in the Console, I return the error below:

glyphicons-halflings-regular.woff2 Failed to load resource: the server responded with a status of 404 (Not Found)

(this in both browsers, including those where icons work);

going in the corresponding folder, the file . woff2 is there ! I tried to remove it and it works, but when another instance of Firefox opens, the file comes back and the icons disappear again.