Nationwide UK doesn't get a Best Buy for Term Deposits - why?

[slippy]

In the (excellent) post

Best Buy Term Deposits (Fixed Lump Sum Savings)

I see Nationwide UK doesn't get a Best Buy for it's 1 year fixed at 3.4%, but Investec does for its equivalent account at 3.0%. Both are protected by the UK FSCS Scheme. Is there a reason for this I'm not aware of?
And all the state-owned Irish banks offering 3.5% get Best Buys, though most of them have in the footnote "has a low credit rating."
The headline rate isn't the only thing to make a product a Best Buy surely?

 

[Lightning]

Hi Slippy,

Investec offered 3.60% for a one year term deposit until very recently. I had a best buy tag there because of that.

I have now removed the best buy tag as they no longer offer 3.60%.

Thanks for pointing this out.