Ceiling insulation - cracks and joints

Good evening,

first of all, a warm hello to everyone. I am new to the forum and this is my first post, or rather my first question right away.

I am currently insulating the basement ceilings in my house. I have chosen a stone wool insulation board with a one-sided light mineral fleece coating. This way, the board will be easy to paint later. The installation of the 100 x 60 cm boards is done using adhesive technology.

Now I have the problem that, due to uneven walls, ceiling brackets for pipes, etc., gaps and cracks have appeared or are appearing in some places on site. Now I am wondering with which suitable material these gaps / cracks can be sealed.

I have been searching online for hours / days and can only find statements like "bla bla bla ... the boards can therefore be installed without gaps and cracks." In my old building, that is impossible ....

How do I seal the gaps / make them tight? Have you had similar experiences? What material did you use? PU foam or acrylic or adhesive or ..... hm ..... no idea.

I would be very grateful for advice and say thank you in advance.

Regards, Dellmo

I used to live in an apartment of a housing association. In the building, the basement and attic were subsequently insulated by a professional company. In the basement, panels were glued under the ceiling and such gaps were closed with a construction foam. No idea what exactly it was, but it was definitely not acrylic or glue. It was supposed to have a certain insulating effect.

Between Styrofoam ETICS boards there is also insulating foam. Now you have rock wool boards, can't the gaps simply be stuffed with rock wool? Finally, then fill with putty.

Thank you for your responses. Yesterday I also had the opportunity to talk again with a plasterer and he said that the cracks and joints are normal and that with this material "it wouldn't be any better" and he also advised me to use foam sealant / PU foam. So that's probably what I will do then .....
Foam the joints, cut off the overflowing material cleanly after drying, plaster the surface and then paint.