Istio blocking connection to MySQL

Hello. I would like to ask a question about something that happens to me in istio (1.12.2). I have two microservices that when I bring them to my kubernetes cluster, they both work correctly and connect perfectly to my MySQL database. The problem occurs when I execute this command “kubectl label namespace default istio-injection=enabled”, to enable the sidecar within the default namespace, then they no longer connect correctly to the database, when removing the injection again, they become to connect correctly. I am a student and I have to do a homework but I do not have much knowledge.
I found this on the internet but it doesn’t seem to work for me