No change of Status in Tijuana, Mexico

Tijuana, Mexico and most other US Visa consulates no longer process Visa Status Changes. For example, if you are in F1 and now have an approved H1 visa and need stamping on your passport, you will have to go back to your native country for stamping. Even H4 to H1 is no longer processed. So no change of visa status stampings are processed.

It is just not Tijuana, Mexico. Most other consulates don't process change of status anymore.
Tijuana, Mexico only accepts extensions or renewals. Also when you go there it is better to go before your I94/stamping expires so that if something goes wrong, you can come back based on your valid I94/stamping. Keep checking updates.

If you need more details check this Murthy Bulletin Link.