Red squiggly lines appear on opening up Pages

Recently every time I open up a Pages document red squiggly lines appear under every second, or third word. Even documents that have been spellchecked and edited get the same treatment and they make reading the document tricky.

I did add a second (Spanish) keyboard to my iPad, which is where the problem occurs, and when the problem started. But having deleted that keyboard the problem remains.

Help please!