In T5950#158024, @werner wrote:

Please check the 2020 certificate by using the details dialog. Has it a valid encryption subkey?

In T5950#157442, @ikloecker wrote:

I'm afraid we need a bit more information. Please tell us the exact steps how you can reproduce the problem.

Moreover, please make sure that there is no text in the field above the table (in the second figure) because this text is used to filter the displayed certificates.