Synchronization from a set date, don't work

Greetings,

We are currently using the Personal version of "Analytics Plus" in our company, and at this time it worked well until the software reached the limitations of the rows and tables.

I understand that Analaytics has its own database that imports from ServiceDesk, we currently have the following data usage:

(We are OK with everything {apparently}, but the sync doesnt work)

We try to synchronize from a more updated date, using the option "Initial data synchronization", but doesn't update the information in Analytics:

It seems that, despite doing this, it keeps the same data imported before the established date, throwing the following error :

I would like to know what is the procedure to eliminate the remaining data, and start from scratch (due to license limitations), since we only need statistics monthly and we are not interested in losing the historical record.

I will be grateful if you can send me this information.

Best regards,