Ribbon Merging - Quick Access Toolbar items' state is not saved when changing an active MDI child form

Here is a code example:

C#
private void ribbonControl1_BeforeUnMerge(object sender, DevExpress.XtraBars.Ribbon.RibbonMergeEventArgs e) {  
            List<BarItemLink> linksToRemove = new List<BarItemLink>();  
            foreach(BarItemLink link in e.MergedChild.Toolbar.ItemLinks) {  
                bool found = false;  
                foreach(BarItemLink mainToolbarLink in this.ribbonControl1.Toolbar.ItemLinks) {  
                    if(link.Item == mainToolbarLink.Item) {  
                        found = true;  
                        break;  
                    }  
                }  
                if(!found)  
                    linksToRemove.Add(link);  
            }  
            foreach(BarItemLink linkToRemove in linksToRemove) {  
                e.MergedChild.Toolbar.ItemLinks.Remove(linkToRemove);  
            }  
        }  

It seems that this issue is not solved. I also added the above piece of code to the main form ribbonControl, but the QAT items are reset when the form focus is changed.
Could you provide me a sample (or change the one provided by me), maybe I'm doing something wrong.

Hello Valentin,
The provided code is intended to synchronize deleted items. I have reviewed your screenshot again and now see that you are hiding items instead of deleting them. In this case, you can use the following code:

C#
private void RibbonControl1_BeforeUnMerge(object sender, DevExpress.XtraBars.Ribbon.RibbonMergeEventArgs e) {  
    var invisiblleItems = this.ribbonControl1.Toolbar.ItemLinks.OfType<BarItemLink>().Where(l => l.Visible == false).Select(i=>i.Item).ToList();  
    foreach (BarItemLink linkToRemove in e.MergedChild.Toolbar.ItemLinks) {  
        if (invisiblleItems.Contains(linkToRemove.Item)) {  
            linkToRemove.Visible = false;  
        }  
    }  

I hope this helps.