Hi Gabriele
There is a procedure that archive the data from task persistence to the archive database. I used these procedures on version 12.6.2:
Stuck In Progress Tasks / Events & Garbage Collection
I don't know if in version 14.2 will work, but you can try this in a non-production environment, or, you can open a support case, they sent it to me when I needed it.
Kind regards,
Gustavo Viggiano