Disappearing signatures

Hello,
I'm havin a problem with singatures in adobe reader.
The company I work for use a service called "connective" to put digital signatures on pdf's using itsme/eid.
After people signed the pdf I can then download them to check if the signature is valid.

However sometimes it happens that I can not see the signature in adobe reader, but when I open it first in google chrome I do see that it's been signed (but there I can not check if it's valid).

This problem only happens to some pdf's and I checked View > Show/Hide > Navigation Panes and "Signatures" is not there for those files. 
 
Can you help me with this problem of the disappearing signatures?