Try looking in Quarantine.
For future reference questions regarding mobile security should be in the Mobile forum section https://forum.avast.com/index.php?board=119.0
You would be best to create a new thread in the Avast Mobile Security section of the forum as mentioned by CraigB.
There is a section for IOS and Android. Use the one that matches your type of phone.
I have never experienced what you have seen, but others that have had file/s quarantined may be able to help you better than me.
I suspect that by "resolving" the issue yesterday, you have already removed the file and any record of it already.