How to update titles and text annotations of subplots located on the same uitab?

% TAB 1 
S.tabH(1) = uitab(S.histoTab, 'Title', 'Error X');

S.P1_histo{1} = subplot(2,2,[1 3], 'Parent', S.tabH(1));
s2.tab1sp1 = hggroup;

S.P1_histo{2} = subplot(2,2,[2 4], 'Parent', S.tabH(1));
s2.tab1sp2 = hggroup;

% TAB 2
S.tabH(2) = uitab(S.histoTab, 'Title', 'Error Y');

S.P2_histo{1} = subplot(2,2,[1 3], 'Parent', S.tabH(2));
title('On Fly'); 
s2.tab2sp1 = hggroup; 

S.P2_histo{2} = subplot(2,2,[2,4], 'Parent', S.tabH(2)); 
title('Static');
s2.tab2sp2 = hggroup;

 %%In the Callback Function

    handles = guidata(source);
    currentTab = find(source.SelectedTab == S.tabH);

    switch currentTab
        case 1

            if ~isempty(handles.R_Site_X_Static_NM_DRF)   
                histogram(handles.R_Site_X_Static_NM_DRF, 'parent',s2.tab1sp2);
                ThreeSig_X_S = 3 * std(handles.R_Site_X_Static_NM_DRF);
                stringH1 = strcat({'Static, '},{'3sig: '}, {num2str(ThreeSig_X_S)});
                title(S.P1_histo{1}, 'Static');
                text(S.P1_histo{1},0, 200, stringH1);

            end

            if ~isempty(handles.R_Site_X_OnFly_NM_DRF)
                histogram(handles.R_Site_X_OnFly_NM_DRF, 'parent', s2.tab1sp1);
                ThreeSig_X_OF = round(3 * std(handles.R_Site_X_OnFly_NM_DRF),3);
                stringH2 = strcat({'3sig: '}, {num2str(ThreeSig_X_OF)}); 
                title(S.P1_histo{2}, 'On Fly');
                text(S.P1_histo{2},0.2, 130, stringH2, 'FontWeight', 'Bold');
            end
         case 2 
        ...

I am getting the title and text annotation only for the second subplot of tab 1. When debugging the code line by line, I get the title and text for the first subplot too, but it later disappears.