Activity display blocked

Hello,
Working with v. 9.3.5, the display of a particular activity is slow and blocked:
- this occurs only for this one,
- the color in the planning is not usual: light orange.
- More info on the activity: management task, status: in progress, planning mode: recurrent. I still can access to the timesheet.
- in the log file in script mode, I get a bunch of getProfile(objectOrIdProject=):2022-04-07 10:35:45.453 ..... SCRIPT .... 134.158.201.4 getAccessControlRights(obj=Activity #580)
2022-04-07 10:35:45.453 ..... SCRIPT .... 134.158.201.4 getProfile(objectOrIdProject=Activity #580)
2022-04-07 10:35:45.493 ..... SCRIPT .... 134.158.201.4 getProfile(objectOrIdProject=)
.... (more than 50)
2022-04-07 10:35:45.493 ..... SCRIPT .... 134.158.201.4 getProfile(objectOrIdProject=) This issue occurs even in admin mode.
I suspect that the slow display is due to the multiple getProfile(objectOrIdProject=) requests.
In admin mode, I checked the base consistency and even ran a repair when no defect was detected.