"I will follow michaels advice and check the timing now"

Why going the harder way first ?

I know not which library you use, but on my I2C functions I can easy see, if start and stop are successful and also if an ACK or NACK was received.

So I can exact determine, if there is something wrong on the data or already on addressing the device.

Furthermore you should insert a ready polling after a byte or page write to be sure, that the write operation was finished.
Also then you can see, if writing was finished to fast, that something was wrong.


Peter