firefox 90 stopped remembering window size

since upgrading to firefox 90, all newly opened firefox windows are very small and need to be manually resized to a usable size.

prior to firefox 90, new windows would be the same size as the last opened window.

running on gnome on wayland with fractional scaling enabled, if that matters.

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: firefox 90.0+build1-0ubuntu0.21.04.1
ProcVersionSignature: Ubuntu 5.11.0-22.23-generic 5.11.21
Uname: Linux 5.11.0-22-generic x86_64
AddonCompatCheckDisabled: False
ApportVersion: 2.20.11-0ubuntu65.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: jbarnett 2823 F.... pulseaudio
BuildID: 20210705185941
CasperMD5CheckResult: unknown
Channel: Unavailable
CurrentDesktop: GNOME
Date: Tue Jul 20 09:23:39 2021
Extensions: extensions.sqlite corrupt or missing
ForcedLayersAccel: False
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
InstallationDate: Installed on 2019-08-17 (703 days ago)
InstallationMedia: Ubuntu 19.04 "Disco Dingo" - Alpha amd64 (20190305.1)
IpRoute:
 default via 192.168.0.1 dev wlp2s0 proto dhcp metric 600
 169.254.0.0/16 dev docker0 scope link metric 1000 linkdown
 172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
 192.168.0.0/24 dev wlp2s0 proto kernel scope link src 192.168.0.25 metric 600
Locales: extensions.sqlite corrupt or missing
MostRecentCrashID: bp-76c5697a-ecec-48ea-b09a-9db310190506
PrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/firefox/omni.ja:greprefs.js:352
PrefSources:
 /usr/lib/firefox/defaults/pref/all-ubuntu-gnome.js
 prefs.js
Profiles: Profile0 (Default) - LastVersion=90.0/20210705185941 (In use)
RunningIncompatibleAddons: False
SourcePackage: firefox
SubmittedCrashIDs: bp-76c5697a-ecec-48ea-b09a-9db310190506
Themes: extensions.sqlite corrupt or missing
UpgradeStatus: Upgraded to hirsute on 2021-07-08 (11 days ago)
dmi.bios.date: 03/25/2021
dmi.bios.release: 1.15
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.15.1
dmi.board.name: 0N338G
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 31
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.15.1:bd03/25/2021:br1.15:svnDellInc.:pnXPS159575:pvr:rvnDellInc.:rn0N338G:rvrA00:cvnDellInc.:ct31:cvr:
dmi.product.family: XPS
dmi.product.name: XPS 15 9575
dmi.product.sku: 080D
dmi.sys.vendor: Dell Inc.