Products getting "kicked" out of the shopping cart

I realized today that products for which I have “Role Based Pricing” enabled will get deleted from the shopping cart after some (short) time. Sometimes immediately, sometimes after some seconds.

I get a message, that the product has been removed because it’s not buyable anymore.
In german: “[productname] wurde aus deinem Warenkorb entfernt, da es nicht mehr gekauft werden kann. Bitte kontaktiere uns, wenn du Hilfe ben?tigst.”

First I thought that I have a general problem. But after disabling Role Based Pricing for single products these products won’t get removed from the cart.

Is there any way to fix this manually?

https://www.ads-software.com/plugins/woocommerce-role-based-price/