KDE with low framerate (skippy mouse pointer) on high res optimus setup

I’m using KDE on a notebook with NVIDIA optimus on a high res (2560x1440) display and the frame rate is quite low, with a skippy mouse pointer. This notebook’s got a RTX 3070 card alongside the Intel build-in. My previous notebook had a fullHD display on a similar setup, but a GTX 1070 instead and was fast and smooth.

Here’s the hardware configration:

Here’s the output of inxi --Fxzc0:

System:    Kernel: 5.13.19-2-MANJARO x86_64 bits: 64 compiler: gcc v: 11.1.0 Desktop: KDE Plasma 5.23.3 Distro: Manjaro Linux
           base: Arch Linux
Machine:   Type: Laptop System: Avell High Performance product: C65 MOB v: Standard serial: <superuser required>
           Mobo: Avell High Performance model: Avell C65 MOB v: Standard serial: <superuser required>
           UEFI: American Megatrends LLC. v: N.1.07AVE00 date: 07/23/2021
Battery:   ID-1: BAT0 charge: 91.6 Wh (100.0%) condition: 91.6/91.6 Wh (100.0%) volts: 13.1 min: 11.6 model: standard
           status: Full
CPU:       Info: 8-Core model: 11th Gen Intel Core i7-11800H bits: 64 type: MT MCP arch: Tiger Lake rev: 1 cache: L2: 10 MiB
           flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 73744
           Speed: 1130 MHz min/max: 800/4600 MHz Core speeds (MHz): 1: 1130 2: 1795 3: 4047 4: 3497 5: 1783 6: 2455 7: 4546
           8: 4565 9: 4143 10: 2004 11: 3010 12: 4579 13: 4598 14: 4418 15: 1086 16: 1080
Graphics:  Device-1: Intel TigerLake-H GT1 [UHD Graphics] vendor: Tongfang Hongkong Limited driver: i915 v: kernel
           bus-ID: 00:02.0
           Device-2: NVIDIA GA104M [GeForce RTX 3070 Mobile / Max-Q] vendor: Tongfang Hongkong Limited driver: nvidia
           v: 495.44 bus-ID: 01:00.0
           Device-3: Chicony HD Webcam type: USB driver: uvcvideo bus-ID: 3-13:5
           Display: x11 server: X.Org driver: loaded: modesetting resolution: 2560x1440~165Hz
           OpenGL: renderer: Mesa Intel UHD Graphics (TGL GT1) v: 4.6 Mesa 21.2.5 direct render: Yes
Audio:     Device-1: Intel Tiger Lake-H HD Audio vendor: Tongfang Hongkong Limited driver: snd_hda_intel v: kernel
           bus-ID: 00:1f.3
           Device-2: NVIDIA GA104 High Definition Audio vendor: Tongfang Hongkong Limited driver: snd_hda_intel v: kernel
           bus-ID: 01:00.1
           Sound Server-1: ALSA v: k5.13.19-2-MANJARO running: yes
           Sound Server-2: sndio v: N/A running: no
           Sound Server-3: JACK v: 1.9.19 running: no
           Sound Server-4: PulseAudio v: 15.0 running: no
           Sound Server-5: PipeWire v: 0.3.40 running: yes
Network:   Device-1: Intel Tiger Lake PCH CNVi WiFi driver: iwlwifi v: kernel bus-ID: 00:14.3
           IF: wlo1 state: up mac: <filter>
           Device-2: Realtek RTL8125 2.5GbE vendor: Tongfang Hongkong Limited driver: r8169 v: kernel port: 3000
           bus-ID: 2d:00.0
           IF: enp45s0 state: down mac: <filter>
Bluetooth: Device-1: Intel AX201 Bluetooth type: USB driver: btusb v: 0.8 bus-ID: 3-14:6
           Report: rfkill ID: hci0 rfk-id: 1 state: up address: see --recommends
Drives:    Local Storage: total: 953.87 GiB used: 97.02 GiB (10.2%)
           ID-1: /dev/nvme0n1 vendor: A-Data model: IM2P33F8BR2-1TB size: 953.87 GiB temp: 28.9 C
Partition: ID-1: / size: 229.38 GiB used: 97 GiB (42.3%) fs: ext4 dev: /dev/nvme0n1p6
           ID-2: /boot/efi size: 96 MiB used: 25.3 MiB (26.3%) fs: vfat dev: /dev/nvme0n1p1
Swap:      Alert: No swap data was found.
Sensors:   System Temperatures: cpu: 55.0 C mobo: 55.0 C
           Fan Speeds (RPM): N/A
Info:      Processes: 357 Uptime: 11m Memory: 15.38 GiB used: 3.76 GiB (24.4%) Init: systemd Compilers: gcc: 11.1.0
           clang: 13.0.0 Packages: 1505 Shell: fish v: 3.3.1 inxi: 3.3.09