Key Signatures after transposing

Dear all,
i have the score of a march written for an Instrument tuned in C.
As my instrument is tuned in Ces (strange, I know) I have to transpose a half tone up.
In musescore 2 I used to change the key signature wich worked properly.

After scoring the whole march, I transposed it from the key signature F major to Fis major.
(The "Trio" from B major to H major).
After transposing the Key Signature was repeated in several measures in the middle of the line (additional to the beginning). The "Trio" also has additional key signatures in some measures before transposing.

I add some screenshots of the score before and after transposing.
I hope they will illustrate my problem.

The additional key signatures cannot be deleted and I don't know why they appear the Signature has not changed.

Thank you in advance for your support.