After data refresh, spikes are seen in the data.

I have a problem for which I cannot find a solution.
When I publish to Power BI Service everything looks fine, see figure 1.
So after an auto refresh at night, data spikes are now seen at 1 a.m. every day, where there is now a double value, see figure 2. This only happens for the current month.

If I retrieve the data from the graph, there are no duplicate values.
The totaled values ​​I have in a card do not include the spikes in the total either.

I've tried turning off incremental refresh, to no avail.
I have tried using a different date picker with no luck.
I have gone through the DAX code but can't find anything there, it is very simple.

Data is retrieved via SQL.

I've been working with Power BI for a few years now and have never seen power bi show wrong like that before.

Your input is very welcome.

Figure1:

Figure 2: