Make a pot of tea, make yourself comfortable and I'll tell you a story.
A long, long time ago ... well not that long really ... around about the start of 2015 ... Sabai Thai opened at 849 - 851 Christchurch Road opposite Baan Thai at 846.
Fast forward about 3 years, to around about the start of 2018, and Sabai Thai moved to Hurlingham House, Manor Rd. It was replaced at 849-851 by Euphoria.
More recently Baan Thai has moved from 846 to 842 and .... a Sabai Thai has opened at 846. Whether it is the same Sabai Thai that used to be at 849-851, and then Manor Road, is something I don't know.
Is that all clear
perhaps you deserve more than a cup of tea
Ps Sabai Thai was always considered legit .... but .... as the saying goes ... YMMV.