So what changed on 26th June?
Companies House have has introduced new Persons of Significant Control forms. Prior to 26th June you would notify Companies House of any changes to PSC details via the Confirmation Statement. From the 26th June you must now notify Companies House via the appropriate PSC form and the Confirmation Statement will no longer be used for this purpose.
The Confirmations Statement should now only be filed to notify Companies House that all the information on the public record is up-to-date, very much like the old Annual Return.
So any changes to PSC details (such as the name, address or a change in PSC structure) must be submitted to Companies House prior to the Confirmation Statement being filed.
Any changes to PSC details must be recorded in the PSC register within 14 days, and filed with Companies House within 14 days, so you have 28 days from the change to record in your PSC register and notify Companies House.