Something odd going on with network routing to Twitter in the UK right now. From a BT Broadband home connection, traffic seems to be flowing via an "mts-internet.net" addresses listed in Moscow. I've tried from a VPN and can access Twitter just fine. Downdectector shows a peak in reports of issues too - https://downdetector.co.uk/status/twitter/.
Tracing route to twitter.com [104.244.42.1] over a maximum of 30 hops:
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