carla, the site at https://internationalbiblestudents.com/history.html does not say JW's (Jehovah's Witnesses) are not International Bible Students, instead it says "Bible Students Are Not Jehovah's Witnesses ". That is very different. The various Bible Students groups (such as Dawn Bible Students) are not a part of International Bible Students Association, but the people working at International Bible Students Association in the UK are Jehovah's Witnesses. Furthermore, the International Bible Students Association in the UK publishes literature of the Jehovah's Witness.
carla, the site you linked to at https://www.friendsofjehovahswitnesses.com/2011/09/01/bible-students-are-not-jehovahs-witnesses/ in Comments section, in a comment by Richard.Tazzyman on September 20, 2018 says "Hello Diana,The IBSA In England is the Legal name used by the JWs In the
UK." In contrast he then says regarding his group (not ISBA in the UK) that "We are the original Bible Students which the JWs broke away from
when Pastor Russell died.We have members all over the world & In the
UK as well."
But, perhaps there is a different IBSA (a non-JW one) than the JW one used in the UK.