Thingspeak: problem with a bar graph

Hi

I'm trying to plot some measured values on bar graphs, but it seems that only a few values are plotted, not all of them.

Here is the code:

readChannelID = ***;
fieldID = 1;
readAPIkey = '****';
%% Read data %%
month = 3;
day = 21;
range = [datetime(2020,month,day,0,0,0),datetime(2020,month,day,23,59,59)];
[data,time] = thingSpeakRead(readChannelID,'Fields',1,'DateRange',range,'ReadKey', readAPIkey);
%% Vizualize data
hours = datetime(0,0,0,hour(time)+1,minute(time),second(time));
hours
data
bar (hours,data,'r');

The graph is plotted but the maximum plotted value is around 25, and the maximum value I get when displaying the value lists is 58.

The last values displayed for data are:

     5
     5
     5
     6
     5
    20
    13
    15
    13
    48
    27
    26
    58
    19
     6
    12

It seems only one value out of 5 is plotted. What did I miss?

Thanks for your help