Can’t search drive files within Gmail anymore

I’ve noticed my queries using the search bar in Gmail don’t return files in my Google Drive anymore. The files used to appear as a suggestion below the bar while I was typing. Is there a way to turn that feature on again?

I found some questions regarding this around 2016, when apparently Google started to demand the activation of a Gmail lab for this to work (Labs are defunct now). I have the impression this feature stopped working for me way after 2016 though.