I've built a pipeline script, which reads some property files and lets the user select some groups and items (it creates parallel stages dynamically). In order to reproduce this bug, please run the Jenkinsfile attached to this issue. You also need to copy all the txt-files to your /tmp directory.
When executing the pipeline for the first time, select "item_grp_1" and at the next stage, check/mark all the three items, then click select. This will dynamically build parallel stages for the selected items. Now for each of the selected item, there's a input message, just click "Continue" and let the pipeline finish successfully.
Now restart the pipeline again and select "item_grp_2" or "item_grp_3" and select only one item. Since there's only one item selected, the script does not spawn parallel stages, but the required input message is not shown. Instead the visualisation from the previous build is shown and cannot be refreshed to see the input message.
Only when accessing the "console output" (in the classic UI) the input can answered.