Man bun undercut hairstyle problem

Here's the thing. I decided to get a bun undercut hairstyle so i started growing my hair. When I went to the hairdresser to have them cut at the sides he cut them higher than I expected and as they should be. So my question is should just wait them grow back even if they'll be shorter than the rest for some time or should I cut them all and start from the beginning?

Any reply will be appreciated