Why doesn't the pattern work in .gitignore?

Question

git

there are files in the git repository directory:
subprojects/subproject1/data/some_text.some_text.graphml
subprojects/subproject1/data/some_dir/some_text.some_text.graphml
I made a template for them in gitignore, which looks like this:
subprojects/subproject1/data/ **/*.graphml
but it doesn't work, files are not ignored anyway. Empirically established that if there is no dot in the file name, i.e. for example, if the file name is subprojects/subproject1/data/some_text.graphml, then the template is triggered and the file is ignored. Tell me, what's the problem? and how to make git ignore a file with a dot in its name?

Answer 1

I created a test repository, and with your template all 3 files are successfully ignored:

subprojects/subproject1/data/some_dir/some_text.some_text.graphml
subprojects/subproject1/data/some_text.graphml
subprojects/subproject1/data/some_text.some_text.graphml

Maybe you have some very old version of git?
And a stupid question: are you sure these files are not already under version control?