Thanks both for the fast replies.
@josh beat me to the screenshot. Thanks, and sorry for my slow reply, I was just triple-checking things to avoid saying anything wrong. Indeed, Safari also shows the error in the console (for the deployed version 1.2.1) but then somehow ends up re-evaluating successfully when the value is set and showing the plots.
So, for Firefox and Chrome maybe, it is just all about that input[...] error in the end. That said, I'm just puzzled why the issue only occurs specifically on the shinyapps.io-hosted app, but neither on a locally-launched app nor on an app launched interactively from the RStudio Cloud. In those last two cases, the plots do show.
We've pushed a fix to the Bioconductor release branch, but it will take a couple of days to go through their build system before being available to install, deploy and test the new version (1.2.2) on shinyapps.io.
In the meantime, @mara, I assume your screenshot is from the deployed app? Because when I launched the app from the RStudio cloud session in Chrome, it shows me the panels.
This last difference (https://rstudio.cloud vs shinyapps.io) is what truly puzzles me.