If I look at the RF spectrum on an MR55 running 26.7, 5GHz now looks good and 2.4GHz seems to still show interfering APs at -40dB, but only for very low signal level ones,the arriva-wifi ones are a bus going past the end of the road about 100m away. The close ones now seem to be showing correctly. It may therefore be fixed as I only upgraded this network about 36 hours ago...
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