Issue with Tiny RTC I2C Modules (DS1307)

So i have the following problem:

when the RTC reaches 8am it shows 12am

this happens between 8am and 4pm, at this period of time the RTC shows a wrong time going from 12am to 8am.

when it reaches 4pm it works normally

This happens when i upload an example code (directly from the library)

I hope you can help me, thank you