Recognize decimal point when importing CSV
This problem is at least 25 years old: when your local Windows standard has the komma as decimal separator, somehow Excel is too stupid to recognize the point as decimal separator when importing a CSV-file. One look in the CSV and you see that it uses the komma between the columns and the point in the numbers. Hard to believe it when you first see this go wrong and then an old man like me tells you this is how Excel works!!! Please, Microsoft, finish your software.
Excel uses your system language settings for separators and decimals. If you import with different settings, YOU need to take the extra steps to define what Excel needs to do OR align your CSV with the correct system settings (propably ; for field separator and , for decimals).
You do sound like an old man (your words..): "it's not working, so the software is flawed".
This is not a software issue, it's a user issue..