Error CRON :Attempting to re-run cron while it is already running

Hello,

I have a very curious thing that I've never had before. Indeed I get the following error in the launch of cron:

Attempting to re-run cron while it is already running

then

Cron run exceeded the time limit and was aborted

I deleted in BD:

DELETE FROM `variable` WHERE name = 'cron_semaphore';
DELETE FROM `variable` WHERE name = 'cron_last';

I also saw that this could come from max_execution_time so I grew it in my php.ini.

I also saw that this could come from search settings so I dropped to 10 the number of items to index per cron.

Unfortunately I still have the same concern.

An idea?

Thank you