When filling out a form, as long as you underline it, it will be extended with the words and cannot be fixed. There are two ways:

1, directly set the cursor where you want to enter the text, then set the cursor at the far right of the underline, and press the Delete key on the keyboard (delete above the arrow keys) to delete it slowly.

2. Select the part of the underline to be entered directly, and then enter the text, so that the text will replace the selected underline position and the underline will not be extended.