PDF turns to RGB when Text is edited

[alexander_duerregger]

Hello!

We have a problem with a PDF. The PDF can be downloaded from: https://1drv.ms/b/s!Aoz65A8erFWChqdWrzIjCXb3ha_TjA

We try to edit text with the Acrobat edit function. As soon as we edit some text the whole PDF turns from CMYK to RGB. Why does this happen an how can we prevent it?

best regards,

alexander

[alexander_duerregger]

Here is a screen recording of the process for better unterstanding: https://goo.gl/u3ShG1