Prophet: Multiplicative seasonality scales down trend values

Jpsy 0
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I am having strange effects when I change my Prophet model from additive to multiplicative seasonality:
While my predictions get a lot better, my trend seems to be multiplied down to about 10% of the expected values.
I would expect the trend to stay in the same value range. Am I wrong?

Example with additive seasonality:

    proph_model = Prophet()
    proph_model.fit(df)

Result as expected: enter image description here

Example with multiplicative seasonality:

    proph_model = Prophet( seasonality_mode="multiplicative" )
    proph_model.fit(df)

Result with better prediction but strangely scaled down trend: enter image description here

I am currently working with latest Prophet 1.1.1 on Python 3.10.6.

facebook-prophet python
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