This is the patch I use to workaround the issue:
diff -Naur a/btrfs-progs-5.4.1/debian/local/btrfs.local-premount
b/btrfs-progs-5.4.1/debian/local/btrfs.local-premount
--- a/btrfs-progs-5.4.1/debian/local/btrfs.local-premount 2020-01-09
17:49:59.000000000 +0100
+++ b/btrfs-progs-5.4.1/debian/local/btrfs.local-premount 2020-04-08
04:19:49.719861972 +0200
@@ -18,7 +18,7 @@
if [ -x /bin/btrfs ]
then
- modprobe btrfs
+ modprobe btrfs || true
# If asked to be quiet, show only errors
[ "${quiet}" = "y" ] && exec >/dev/null
/bin/btrfs device scan
