How can I solve Data loss in Serial.readStringUntill() with I2C communication?

I am using Arduino Nano in my project, I have to use Serial Communication and I2C communication in this device.
But what I found that if using I2C communication simultaneously, then data loss found in Serial.readStringUntill() .

If I am using Serial.readStringUntill() separately(without I2C communication) then no data loss is found.

so there is any problem to work with serial Communication and I2C communication simultaneously?

Seeing your program would be helpful, don't you think ?
For instance, without it we don't know which pins you have used