I can also assure that the grosvenor you work at must be 1 of a kind, the minimum raise shd be the difference between the previous raise and the bet/bb before added on again.
i.e blind 200/400 raise to 1200 minimum raise now has to be the difference added on again so the min raise now is 2000 to play
i have worked for grosvenor/stanleys and now at DTD. Some strange rules being implemented through the UK.