UTF-8 warning when upgrading Tiki18 to Tiki19

• Error
• Consistency

I switch a Tiki18 to a Tiki19.

During the install on the database step, I had a warning about "UTF-8 encoding" while my tables were properly upgraded to utf8mb4_unicode_ci.

Following the links to the doc doesn’t really help

On a second attempt (local) I didn’t upgrade previously the table and applied the database upgrade. After upgrading the database I checked my database (phpmyadmin) most of the tables were utf8mb4_unicode_ci while a few (see the list below) were still UTF-8 unicode;
tiki_acct_journal
tiki_acct_stack
tiki_banning

The database upgrade process ended successfully but with error report:

Upgrade operations executed successfully: 668 SQL queries.

Operations failed: 6 SQL queries. Display details.

During an upgrade, it is normal to have SQL failures resulting with Table already exists messages.
ALTER TABLE `sessions` convert to character set DEFAULT COLLATE DEFAULT Table 'tsaharoniki_tiki19.sessions' doesn't exist ALTER TABLE `tiki_banning` convert to character set DEFAULT COLLATE DEFAULT Invalid default value for 'date_to' ALTER TABLE `tiki_acct_journal` convert to character set DEFAULT COLLATE DEFAULT Invalid default value for 'journalDate' ALTER TABLE `tiki_acct_stack` convert to character set DEFAULT COLLATE DEFAULT Invalid default value for 'stackDate' ALTER TABLE `tiki_banning` CHANGE `message` `message` text COLLATE utf8mb4_unicode_ci Invalid default value for 'date_to' ALTER TABLE `sessions` CHANGE `data` `data` text COLLATE utf8mb4_unicode_ci NOT NULL Table 'tsaharoniki_tiki19.sessions' doesn't exist

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I refreshed and they were no more errors.

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