Kernels above 5.4 work one time after running mkinitcpio -P in kernel 5.4 or booting other kernel in initramfs mode

Hello, maybe somebody can help with my issues. Once I installed Manjaro in efi mode on my PC. It worked fine. The knewest kernel at that point was 5.10 and it worked well. Alas that version of installer couldn’t manage to setup encryption correctly. Eventually I removed that Manjaro and installed it again using a newer installer. Newer installer did everything perfect except it failed installing gpu drivers and I had to decrypt the installation and chroot using live media. Chroot let me update the gpu driver and it worked well until I rebooted. All kernels above 5.4 (LTS) now behave in such manner:
Manjaro boots. I have Latte dock installed. It is the only thing that loads. Afterwards it takes around 10 minutes for plasma to load (taskbars, menus, desktop selection animation and icons, etc). Apps are slow. Most of the apps don’t launch. Terminal works but some commands just hang forever. System tells they are not responding. Audio and Internet don’t work (devices aren’t detected). When I reboot or shutdown the system it hangs. If I boot using initramfs it works well. Kernel 5.4 works well without initramfs. If I run mkinitcpio -P kernels above 5.4 (5.11, 5.12 for examples) will boot normally 1-2 times and eventually fail to detect some hardware and become extremely slow the way I described earlier.

My computer also has Solus installed on seperate HDD. Solus has kernel 5.11 at the moment and works perfectly.

It seems kernel 5.10 got promoted to LTS. I am trying it at the moment. It doesn’t work.

My inxi -F:

System:    Host: snail-computer Kernel: 5.4.123-1-MANJARO x86_64 bits: 64 Desktop: KDE Plasma 5.21.5 Distro: Manjaro Linux 
Machine:   Type: Desktop Mobo: ASRock model: Z370 Gaming K6 serial: <superuser required> UEFI: American Megatrends v: P4.20 
           date: 10/31/2019 
CPU:       Info: 6-Core model: Intel Core i7-8700K bits: 64 type: MT MCP cache: L2: 12 MiB 
           Speed: 800 MHz min/max: 800/4700 MHz Core speeds (MHz): 1: 800 2: 800 3: 800 4: 800 5: 800 6: 800 7: 800 8: 800 
           9: 800 10: 800 11: 800 12: 800 
Graphics:  Device-1: NVIDIA TU102 [GeForce RTX 2080 Ti Rev. A] driver: nvidia v: 465.31 
           Display: x11 server: X.Org 1.20.11 driver: loaded: nvidia resolution: 2560x1440 
           OpenGL: renderer: NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2 v: 4.6.0 NVIDIA 465.31 
Audio:     Device-1: Intel 200 Series PCH HD Audio driver: snd_hda_intel 
           Device-2: NVIDIA TU102 High Definition Audio driver: snd_hda_intel 
           Sound Server-1: ALSA v: k5.4.123-1-MANJARO running: yes 
           Sound Server-2: PulseAudio v: 14.2 running: yes 
Network:   Device-1: Intel Ethernet I219-V driver: e1000e 
           IF: eno1 state: up speed: 1000 Mbps duplex: full mac: 70:85:c2:80:32:e0 
           Device-2: Intel I211 Gigabit Network driver: igb 
           IF: enp5s0 state: down mac: 70:85:c2:80:32:de 
Bluetooth: Device-1: Cambridge Silicon Radio Bluetooth Dongle (HCI mode) type: USB driver: btusb 
           Report: rfkill ID: hci0 state: up address: see --recommends 
Drives:    Local Storage: total: 23.68 TiB used: 6.04 TiB (25.5%) 
           ID-1: /dev/sda vendor: Western Digital model: WUH721414ALE6L4 size: 12.73 TiB 
           ID-2: /dev/sdb vendor: HGST (Hitachi) model: HUH721212ALE604 size: 10.91 TiB 
           ID-3: /dev/sdc type: USB vendor: Transcend model: JetFlash Transcend 32GB size: 28.48 GiB 
Partition: ID-1: / size: 10.76 TiB used: 6.04 TiB (56.1%) fs: ext4 dev: /dev/dm-0 
           ID-2: /boot/efi size: 299.4 MiB used: 480 KiB (0.2%) fs: vfat dev: /dev/sdb1 
Swap:      ID-1: swap-1 type: partition size: 69.02 GiB used: 0 KiB (0.0%) dev: /dev/dm-1 
Sensors:   System Temperatures: cpu: 31.0 C mobo: N/A gpu: nvidia temp: 61 C 
           Fan Speeds (RPM): N/A gpu: nvidia fan: 0% 
Info:      Processes: 291 Uptime: 29m Memory: 62.75 GiB used: 4.31 GiB (6.9%) Shell: Bash inxi: 3.3.04

If it worked before without encryption, I would rather guess that the problem is the encryption. The bottleneck could be also the spinning drives in general or maybe the ioscheduler (with spinning drives you get a better performance with the bfq scheduler than the mq-deadline, which is more optimized for SSDs)