If you have installed multiple browser Apps on your iPad, verify that you have selected Safari as your default web browser in iPad settings:
Settings > Apps > Default Apps > Browser App - select Safari from the list of available browsers

If you have selected Safari as the default - and Chrome continues to open unexpectedly - change the selection to a different alternative browser (e.g. Firefox) - and then verify that the new selection has occurred.
If the selection has demonstrably changed the default, return the default selection to Safari.