Could be faulty or could need an update,
Settings > System > Remotes & Accessories > Chromecast Remote.
You can also buy a new remote if the seller does not get back to you,
Thanks for your reply, the unit is up to date but the problem hasn't gone away, the seller keeps asking to try high grade energizer batterys,I have used the google ones that came with the unit plus two good brand alkaline and rechargables but same problem.
Thanks again for your attention.