The last Sunday we did echo of the arrival of Audacity 2.4.0. It was a major update that came with changes such as official compatibility with macOS Catalina or support for Opus, but it also introduced a change that was not planned. It is a bug that they have considered serious enough to stop offering its most modern version and return to the previous one, as we can see in its download page.
Although there has been no official statement, they have mentioned that Audacity 2.4.0 introduced a bug that caused audio loss or corruption. Therefore, it is recommended not to update to the latest version, which can be a problem if we are using the Flatpak package because it is one of the first to update and the new installment with the serious bug was already available.
Have you upgraded to Audacity 2.4.0? Careful with this
We currently believe that the error occurs when you have two projects open at the same time and you paste the audio from one project to another. Thanks to Jack L from FreeBSD for alerting us to the problem and taking steps to reproduce it.
At the moment and until the project releases an update correcting the problem, it is best to stay with v2.3.3 of the software. For those of you who have already updated, there is a solution or precaution we can take: we have to make sure that we will only have one project open. From what it seems, the more windows or instances of Audacity we have open, the bigger the problem can be.
Without a more extensive official statement, it is impossible to know when they will launch the more than likely Audacity 2.4.1 that corrects this bug but, considering that they are already aware of its existence, the new version should arrive in a matter of hours or days. Until then, Linux users can take advantage of the laziness of the Snap packages and use their version that had not yet been updated. Every cloud has a silver lining.