Nested option groups throw with "template or render function not defined" on input

[RevyakinMB]

• I have searched the issues of this repository and believe that this is not a duplicate.

Version

1.6.3

Environment

Ubuntu 18.04.1/Firefox 78.0.1/AntD 1.6.3; codesandbox.io

Reproduction link

Steps to reproduce

• include SelectOptGroup into another SelectOptGroup of Select component;
• start typing one of the options' value (11, 12, ...) into Select.

What is expected?

Nothing should change apart from text typed in.

What is actually happening?

Content of nested SelectOptGroups disappears, nested SelectOptGroups start displaying like if they were SelectOption components and console contains error messages: "Failed to mount component: template or render function not defined."

[RevyakinMB]

Looks like it crashes independently of filterOption prop value.
I've updated the code on CodeSandbox and the first message.

[Rodimusbot]

Same problem here. Can't search option group..

[github-actions]

This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 7 days

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.