I’ve just updated my iPhone to 27.0 and I found that “Connectivity Assist” and “ Limit IP address tracking” were automatically enabled for my home WiFi networks – I had Limit IP address tracking disabled before the upgrade. Connectivity Assist uses your mobile data network to provide a more reliable Internet experience according to Apple but in fact completely bypassed my PiHole DNS so Advertisements were popping up everywhere! I’ve now disabled both features and I back to having an Ad free life for most of the time…
Source: r/pihole · by /u/TopCat0160