Bug ! : Display subject-location-chair info on the same line in calendar

Hello a found a strange think on the client of my collegue

I migrate the client of a user.

All the data he created, had not a normal display (old and new data). Data from other user are normal display.

Data subject - location - chair in caladendar:

unNormal: display it in only one line

Normal : display in 3 line

If you have info thank you for the help.

Fred