Failed to obtain created call matching lc ID

[Yellow_Flash]

Hi,

we are running 3CX v20 update 4(Build 487) on windows server.
I've done firewall checker, and it passed without any issue.
We are facing a lot of issue now.
The issue i want to focus here is, an error message being shown on windows app.
I'm attaching the screenshot here.
Can someone please let me know what is the reason for this?
This error is coming up every time the client re-launch's the app.
The App version is 20.0.580.0

Thank you for the help