Stock-chart not saved correctly

I created a calc chart to display min and max temperature per day and chose ‘stock’ as it creates vertical lines for each day. Looks good. However, after saving and later reloading, the chart looks entirely different. Looking at the data ranges, they have changed. Maybe I misunderstand something or do something wrong, so please advise me. (LO V7.2.7.2)
Chart before saving (correct):

Unfortunately I cannot upload a second img (I am new in this group).
Libre Office V7.2.7.2 / OS: Win10 Pro / File saved as .ods
I’d love to upload the file but regrettably I do not know how to do.

In order to be able to help you as quickly as possible, we need to know your operating system.
Please also state the file type in which you have saved your file.

All important information about your initial question should be present in the initial question box, otherwise edit and complete it., to do it.

Please do not use answers (solutions) or comments for this.

If you have already fulfilled some of these requirements, so much the better. Thanks.

Upload a file here so that someone can examine it.

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Thank you very much for your assistance.

Are you saving as .ods?

You can upload .ods files in same way as you have uploaded the image: use the Upload icon at top of the post edit box.