Quick Noddle Quetion

[86DA]

I have been registered with noddle for 3 to 4 years. My credit rating when I joined was 3/5 which improved over time to 5/5.

My borrowing hasn't really changed other than moving a credit card balance around, but my rating has gone down to 4/5.

The only thing a can think of is I cancel a Barclaycard which I'd had for about 12 years with a limit of £12k, only to apply for another Barclaycard to get a 0% rate which only had a limit of £5k.

Could that have lowered my score?

Thanks

[86DA]

Quick Update.

Gone back up to 5/5 for no apparent reason.