HEVC x265 10-bit not playing on Ubuntu 20.04

I know similar questions have been asked countlessly on this platform, but none seem to have helped me. For a while now, I've been able to play x265 10-bit videos on my system using mpv media player but after updating to Ubuntu 20.04, the videos have reverted back to how they playing before which was terrible lags, unsynchronised sub/video, and sometimes the video won't even show while the audio keeps going. I experienced these problems before but after getting the gstreamer1.0-libde265 package, the issue was resolved, at least on mpv. All x265 videos were playing smoothly. But since the update, I haven't been able to play x265 videos smoothly on mpv any longer, or on any media player for that matter. Although I can still play them smoothly on windows. I'm assuming it's because the ppa I used to add the package mentioned above was disabled on upgrade to 20.04.

Incase anyone needs info, here's the output from vainfo:

libva info: VA-API version 1.7.0
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/iHD_drv_video.so
libva info: Found init function __vaDriverInit_1_7
libva error: /usr/lib/x86_64-linux-gnu/dri/iHD_drv_video.so init failed
libva info: va_openDriver() returns 1
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_1_6
libva info: va_openDriver() returns 0
vainfo: VA-API version: 1.7 (libva 2.6.0)
vainfo: Driver version: Intel i965 driver for Intel(R) CherryView - 2.4.0
vainfo: Supported profile and entrypoints
      VAProfileMPEG2Simple            : VAEntrypointVLD
      VAProfileMPEG2Simple            : VAEntrypointEncSlice
      VAProfileMPEG2Main              : VAEntrypointVLD
      VAProfileMPEG2Main              : VAEntrypointEncSlice
      VAProfileH264ConstrainedBaseline: VAEntrypointVLD
      VAProfileH264ConstrainedBaseline: VAEntrypointEncSlice
      VAProfileH264Main               : VAEntrypointVLD
      VAProfileH264Main               : VAEntrypointEncSlice
      VAProfileH264High               : VAEntrypointVLD
      VAProfileH264High               : VAEntrypointEncSlice
      VAProfileH264MultiviewHigh      : VAEntrypointVLD
      VAProfileH264MultiviewHigh      : VAEntrypointEncSlice
      VAProfileH264StereoHigh         : VAEntrypointVLD
      VAProfileH264StereoHigh         : VAEntrypointEncSlice
      VAProfileVC1Simple              : VAEntrypointVLD
      VAProfileVC1Main                : VAEntrypointVLD
      VAProfileVC1Advanced            : VAEntrypointVLD
      VAProfileNone                   : VAEntrypointVideoProc
      VAProfileJPEGBaseline           : VAEntrypointVLD
      VAProfileJPEGBaseline           : VAEntrypointEncPicture
      VAProfileVP8Version0_3          : VAEntrypointVLD
      VAProfileVP8Version0_3          : VAEntrypointEncSlice
      VAProfileHEVCMain               : VAEntrypointVLD

And here's the output from lscpu:

Architecture:                    x86_64
CPU op-mode(s):                  32-bit, 64-bit
Byte Order:                      Little Endian
Address sizes:                   36 bits physical, 48 bits virtual
CPU(s):                          2
On-line CPU(s) list:             0,1
Thread(s) per core:              1
Core(s) per socket:              2
Socket(s):                       1
NUMA node(s):                    1
Vendor ID:                       GenuineIntel
CPU family:                      6
Model:                           76
Model name:                      Intel(R) Celeron(R) CPU  N3060  @ 1.60GHz
Stepping:                        4
CPU MHz:                         1968.194
CPU max MHz:                     2480.0000
CPU min MHz:                     480.0000
BogoMIPS:                        3200.00
Virtualization:                  VT-x
L1d cache:                       48 KiB
L1i cache:                       64 KiB
L2 cache:                        2 MiB
NUMA node0 CPU(s):               0,1
Vulnerability Itlb multihit:     Not affected
Vulnerability L1tf:              Not affected
Vulnerability Mds:               Mitigation; Clear CPU buffers; SMT disabled
Vulnerability Meltdown:          Mitigation; PTI
Vulnerability Spec store bypass: Not affected
Vulnerability Spectre v1:        Mitigation; usercopy/swapgs barriers and __user
                                  pointer sanitization
Vulnerability Spectre v2:        Mitigation; Full generic retpoline, IBPB condit
                                 ional, IBRS_FW, STIBP disabled, RSB filling
Vulnerability Srbds:             Not affected
Vulnerability Tsx async abort:   Not affected
Flags:                           fpu vme de pse tsc msr pae mce cx8 apic sep mtr
                                 r pge mca cmov pat pse36 clflush dts acpi mmx f
                                 xsr sse sse2 ss ht tm pbe syscall nx rdtscp lm 
                                 constant_tsc arch_perfmon pebs bts rep_good nop
                                 l xtopology tsc_reliable nonstop_tsc cpuid aper
                                 fmperf tsc_known_freq pni pclmulqdq dtes64 moni
                                 tor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse
                                 4_1 sse4_2 movbe popcnt tsc_deadline_timer aes 
                                 rdrand lahf_lm 3dnowprefetch epb pti ibrs ibpb 
                                 stibp tpr_shadow vnmi flexpriority ept vpid tsc
                                 _adjust smep erms dtherm ida arat md_clear

P.S. Sorry for all the ranting, I'm a noob, so a low-level explanation would be much appreciated.