Reply, forward, and mark-as-read unavailable/impossible on some messages

[FCalderoni]

Hello,

I have a random problem which is quite annoying.
Some messages in the inbox do not enable any action (reply, reply-to-all, forward, mark-as-read). Like this (see the red oval, the options are greyed).

One message above, all is fine

It does not stay like that luckily. After some times (or restarts) it seems to go back to normal. But it is certainly annoying...

Thanks