New anki scheduler removes some days from my heatmap and streak

[oj229]

Problem description

When updating anki to latest version (2.1.48) and being prompted to update scheduler, once the scheduler is installed the heatmap loses 2 days of reviews from its history. these are two days a few months back so is quiet odd. Resets the streak too.
Re-downloading the info from ankiweb then removes the scheduler and restores the days but I cannot import decks unless I have the scheduler and the newest version of anki.
No recent time zone changes. It is literally this issue above.
Clicking on the days and any other days that do have a history on the heat map does not show any cards in the card browser for any day at all.

Checklist

Please replace the space inside the brackets with an x if the following items apply:

• I've restarted Anki to see if it helps
• I've verified that I use the latest version of the add-on by redownloading it from AnkiWeb
• I've verified that I use the latest version of Anki by checking at https://apps.ankiweb.net#download
• I've tried to disable other add-ons to see if there are any interactions present
• My issue disappears when I hold shift while starting Anki.
• I've checked if anyone else reported this problem before by looking through the issue reports. I also checked to see if there is a section about known issues in the add-on description, documentation, or README.

Information about your Anki set-up

Please open Anki, go to Help → About, click on "Copy Debug Info", and paste the result between the backticks below (if the button does not appear you are using an older version of Anki 2.1 and will need to update first):

    
    Anki 2.1.48 (fb07bad3) Python 3.8.6 Qt 5.14.2 PyQt 5.14.2
    Platform: Windows 10
    Flags: frz=True ao=True sv=2
    Add-ons, last update check: 2021-09-21 15:40:06
    
    
    ===Add-ons (active)===
    (add-on provided name [Add-on folder, installed at, version, is config changed])
    Image Occlusion Enhanced for Anki 21 alpha ['1374772155', 2020-04-28T03:21, 'None', '']
    Night Mode ['1496166067', 2020-01-31T08:45, 'None', '']
    Review Heatmap ['review_heatmap', 2020-04-30T14:23, 'None', '']
    load balancer ['1417170896', 2020-08-06T00:58, 'None', '']
    
    ===IDs of active AnkiWeb add-ons===
    1374772155 1417170896 1496166067
    
    ===Add-ons (inactive)===
    (add-on provided name [Add-on folder, installed at, version, is config changed])
    Heatmap ['1722241614', 2019-08-18T16:35, 'None', '']
    Hierarchical Tags Addon 20  21 ['1835859645', 2020-01-31T08:43, 'None', '']
    Percentage Heatmap ['1314463504', 2021-01-06T03:23, 'None', '']
    Postpone cards review ['1152543397', 2021-02-13T16:47, 'None', '']
    ReviewHeatmap ['723520343', 2019-08-03T16:14, 'None', '']

Error message (if any)

If you've received an error message, please copy and paste it between the backticks below: