Don’t Do This, Your Majesty!

The Empire’s strongest Knight, Rosetta, has already returned to the past four times in an attempt to save the prince from assassination. In this life, she tries to hide her abilities and protect the Crown Prince by working as a maid, not an escort knight.
“You said you wanted me,” said the feisty prince.
“I meant I wanted your safety.”
“Similar meaning.” Very, very dangerous.
“So don’t talk to me, open your mouth, Rose.”
“Don’t do this, Your Majesty!”

A knight who wants to save her liege but was unable to blinded by her being unable to protect her liege she turns back time  so as to be able to protect her master now she has become stuck in a loop  unless she saves her liege. Only then would she be able to escape the loop.