Repeater fields are not updated in drafts

Hello,

In blueprints I have content blocks (mixin) with content fields - richedior, dropdowns etc. - it doesn’t matter, filling everything works fine, but now I’m focused on Previews and Drafts for better experience creating a content on website - it is the main requirement of the customer. So I enabled drafts for entries. Creating the draft works perfectly - every content field is duplicated into draft (repeaters, mediafinder, text etc.). I can edit fields and save them for current draft, go back to draft and edit further - no problem.

But big problem occurs when using the draft. It will replace primary record but only with other fields than repeater (didn’t test every field, but text, mediafinder, textarea,… are replaced correctly for draft’s one). In repeater fields remains always the old primary content and not the content created in draft, so it will “delete” finished draft with content for example in rich editor etc. (all are in repeater → content blocks). It doesn’t matter if the repeater filed is in Mixin or not, it can be defined directly in Entry blueprint with activated drafts.

This error appears in new blueprints too - for example with one dropdown field and one repeater field only - so it is not caused by my defined blueprints.

I tried to update from PHP 8.0.2 and Laravel 9 to PHP 8.2 and Laravel 10 - no effect.

October CMS version latest: v3.7.4

I contacted support two moths ago with no progress or information.

Does anyone have the same problem?
Thank you for your help.