Ubuntu 20.04LTS: Ralink RT2561/RT61 keeps deauthenticating

Recently backed up the home folder from a 16.04 LTS install, wiped the disk and did a fresh install of 20.04 LTS, and restored the home folder from the backup. Since then, wifi connects but is slow and regularly drops authentication.

I've tried reloading the wireless kernel module, changing the wifi powersaving settings, and deactivating the N-mode of the driver, with no results.

I think I might need to either recompile the wifi drivers or adjust the kernel version, but I'm not sure which, and I'd rather not touch the kernel if I don't have to. Can anyone offer any insight into which one is likely to be the issue?

sudo lshw -C network:

*-network                 
   description: Ethernet interface
   product: 88E8056 PCI-E Gigabit Ethernet Controller
   vendor: Marvell Technology Group Ltd.
   physical id: 0
   bus info: pci@0000:02:00.0
   logical name: enp2s0
   version: 12
   serial: 00:1d:60:57:d3:e3
   capacity: 1Gbit/s
   width: 64 bits
   clock: 33MHz
   capabilities: pm vpd msi pciexpress bus_master cap_list rom ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
   configuration: autonegotiation=on broadcast=yes driver=sky2 driverversion=1.30 latency=0 link=no multicast=yes port=twisted pair
   resources: irq:28 memory:fe9fc000-fe9fffff ioport:d800(size=256) memory:fe9c0000-fe9dffff
*-network
   description: Wireless interface
   product: RT2561/RT61 802.11g PCI
   vendor: Ralink corp.
   physical id: 1
   bus info: pci@0000:05:01.0
   logical name: wlp5s1
   version: 00
   serial: 00:18:f8:b0:fd:53
   width: 32 bits
   clock: 33MHz
   capabilities: pm bus_master cap_list ethernet physical wireless
   configuration: broadcast=yes driver=rt61pci driverversion=5.11.0-37-generic firmware=0.8 ip=192.168.0.112 latency=64 link=yes multicast=yes wireless=IEEE 802.11
   resources: irq:17 memory:febf8000-febfffff
*-network
   description: Wireless interface
   physical id: 1
   bus info: usb@1:3
   logical name: wlx0015af2398bc
   serial: 00:15:af:23:98:bc
   capabilities: ethernet physical wireless
   configuration: broadcast=yes driver=rtl8187 driverversion=5.11.0-37-generic firmware=N/A link=no multicast=yes wireless=IEEE 802.11

ifconfig -a:

enp2s0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 00:1d:60:57:d3:e3  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 17  

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 8827  bytes 790555 (790.5 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 8827  bytes 790555 (790.5 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlp5s1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.0.112  netmask 255.255.255.0  broadcast 192.168.0.255
        inet6 fe80::3b66:3466:167d:f349  prefixlen 64  scopeid 0x20<link>
        ether 00:18:f8:b0:fd:53  txqueuelen 1000  (Ethernet)
        RX packets 25701  bytes 20660841 (20.6 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 23721  bytes 6775707 (6.7 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlx0015af2398bc: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 00:15:af:23:98:bc  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

sudo iwconfig:

lo        no wireless extensions.

enp2s0    no wireless extensions.

wlx0015af2398bc  IEEE 802.11  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=20 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          
wlp5s1    IEEE 802.11  ESSID:"00placeholder00"  
          Mode:Managed  Frequency:2.412 GHz  Access Point: 94:10:3E:A8:9C:4E   
          Bit Rate=1 Mb/s   Tx-Power=20 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:on
          Link Quality=64/70  Signal level=-46 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:199  Invalid misc:3999   Missed beacon:0

lspci:

05:01.0 Network controller: Ralink corp. RT2561/RT61 802.11g PCI

dmesg:

[ 2348.175565] wlp5s1: authenticate with a2:2b:b0:ea:23:7a
[ 2348.190043] wlp5s1: send auth to a2:2b:b0:ea:23:7a (try 1/3)
[ 2348.392544] wlp5s1: send auth to a2:2b:b0:ea:23:7a (try 2/3)
[ 2348.596457] wlp5s1: send auth to a2:2b:b0:ea:23:7a (try 3/3)
[ 2348.800346] wlp5s1: authentication with a2:2b:b0:ea:23:7a timed out