I bought a Tesco Hudl tablet a while ago.
I really like it!
After a while I started getting intrusive ads.
I installed Adblock Plus and the ads stopped.
About two weeks ago I noticed the little Adblock logo was no longer showing.
I went into App settings and discovered it had disconfigured itself and was no longer blocking ads.
But, I did not reconfigure it, as the ads had stopped.
Still not getting ads without Adblock.
Another of life's mysteries!