Various Mismatch errors when upgrading to 9.0.3

Dear SugarCRM Community, 

I'm attempting to upgrade a site from SugarCRM Pro 8.0.6 to Pro 9.0.3. Heath checks all run without any serious issues. However when run the upgrade process, the process stops at the Post Upgrade section. After reviewing the log, I see numerous errors similar to below: 

Wed, 24 Jun 2020 17:40:01 +1000 [Upgrader] - Running sql: 
/* INDEXES */
/*INDEX MISMATCH WITH DATABASE - idx_leads_tmst_id - ROW <name> idx_leads_tmst_id <type> index <fields>[0] => 'team_set_id' */
/* VARDEF - idx_leads_tmst_id - ROW<name> idx_leads_tmst_id <type> index <fields>[0] => 'team_set_id' [1] => 'deleted' */
ALTER TABLE leads DROP INDEX idx_leads_tmst_id
ALTER TABLE leads ADD INDEX idx_leads_tmst_id (team_set_id,deleted);
Wed, 24 Jun 2020 17:40:02 +1000 [Upgrader] - Running sql: 
/*COLUMNS*/
/*MISMATCH WITH DATABASE - description - ROW [name] => 'description' [type] => 'mediumtext' */
/* VARDEF - description - ROW[name] => 'description' [vname] => 'LBL_DESCRIPTION' [type] => 'text' [comment] => 'Full text of the note' [full_text_search] => 'Array ( [enabled] => 1 [searchable] => 1 [boost] => 0.66 ) ' [rows] => '6' [cols] => '80' [duplicate_on_record_copy] => 'always' [audited] => '' [massupdate] => '' [comments] => 'Full text of the note' [duplicate_merge] => 'enabled' [duplicate_merge_dom_value] => '1' [merge_filter] => 'disabled' [calculated] => '' [required] => '' */
/*MISMATCH WITH DATABASE - resolution - ROW [name] => 'resolution' [type] => 'mediumtext' */
/* VARDEF - resolution - ROW[name] => 'resolution' [vname] => 'LBL_RESOLUTION' [type] => 'text' [full_text_search] => 'Array ( [enabled] => 1 [boost] => 0.65 [searchable] => 1 ) ' [comment] => 'The resolution of the case' [audited] => '1' [massupdate] => '' [comments] => 'The resolution of the case' [duplicate_merge] => 'enabled' [duplicate_merge_dom_value] => '1' [merge_filter] => 'disabled' [calculated] => '' [rows] => '4' [cols] => '20' [help] => 'Please provide sufficient detail to save you, or a colleague, time when reviewing for a similar case. (More than 30 characters)' [required] => '' */
/*MISMATCH WITH DATABASE - work_log - ROW [name] => 'work_log' [type] => 'mediumtext' */
/* VARDEF - work_log - ROW[name] => 'work_log' [vname] => 'LBL_WORK_LOG' [type] => 'text' [full_text_search] => 'Array ( [enabled] => 1 [boost] => 0.64 [searchable] => 1 ) ' [duplicate_on_record_copy] => 'always' [comment] => 'Free-form text used to denote activities of interest' [audited] => '1' [massupdate] => '' [comments] => 'Free-form text used to denote activities of interest' [duplicate_merge] => 'enabled' [duplicate_merge_dom_value] => '1' [merge_filter] => 'disabled' [calculated] => '' [rows] => '4' [cols] => '20' [required] => '' */
ALTER TABLE cases modify COLUMN description text NULL , modify COLUMN resolution text NULL , modify COLUMN work_log text NULL

Most the Mismatch errors relate to certain description fields not being of type "text", as you can see above. The error is indicating that the Column in the relevant table is "mediumtext", however this is not the case. In my database they are "text".  I do not get these errors when running a Quick Repair and Rebuild. 

I have had a look at the relevant VarDef.php files and can confirm that the fields are being set as "text".

I have tested to see if the VarDef Rebuild works by changing one of the description fields to "mediumtext" when I run the QRR, I then get the error that there is a mismatch and I have the chance to execute the script to fix it. This then changes the field back to "text".

I'm finding it difficult to see why the upgrade process thinks that these fields are incorrect. I'm wondering if anyone else has come across this issue?

The next steps I will trying are upgrading to 9.0.0 first then doing some minor version upgrades. Or trying the silent upgrade process. 

Thanks in advance for your assistance.