We should always follow the more prevalent and most acceptable version, rather than exceptions.
Here's a link on the topic https://writingexplained.org/tee-shirt-or-t-shirt
At the bottom of the article is this summary:
T-shirt is the overwhelmingly predominant version.
Tee shirt rarely appears in print. Avoid it in your writing.
Hope this helps.
Below is the link to the relative usage statistics of T-shirt vs. other variants; as per the article I cited in my above message.