Hi @banijadev,
Thanks for getting in touch. I’ve reviewed your other support topic in the fixing WordPress forums, including the very useful video you provided.
When trying to replicate the same issue on some test sites I don’t encounter the same. As what you’re encountering may be a multi-party conflict, can you either check does the same occur with a disposable WordPress site, or can you share if the same occurs on your site while using the Health Check & Troubleshooting plugin – with only the Performance Lab plugin enabled via troubleshooting mode.
I’m also happy to check this further if you wish to post your Site Health information. That way I can ensure I have the same setup with WordPress version and third party plugin environment.