Bug with ASS Subtitle File while playing Bluray or above 2K Video

Hello, without further ado, actually this bug has been around for a very long time. I'm sure this is a bug but it was never fixed and don't understand why it wasn't fixed.

So if I watch a movie with Bluray quality or above 2K and then use subtitles in ASS format, the text will definitely turn black. It's different when using the SRT text format, it will appear to be normal (white). For the record, the subtitles that I use in the ASS format, none of the styles have been changed, which is the default.

I don't know what happened, maybe those of you who know about this can explain it? Here are the video file details :

Video
ID                          : 1
Format                      : HEVC
Format/Info                 : High Efficiency Video Coding
Format profile              : Main 10@L5.1@High
HDR format                  : SMPTE ST 2086, HDR10 compatible
Codec ID                    : V_MPEGH/ISO/HEVC
Duration                    : 3 h 1 min
Bit rate                    : 3 364 kb/s
Width                       : 3 840 pixels
Height                      : 2 020 pixels
Display aspect ratio        : 1.901
Frame rate mode             : Constant
Frame rate                  : 23.976 (24000/1001) FPS
Color space                 : YUV
Chroma subsampling          : 4:2:0 (Type 2)
Bit depth                   : 10 bits
Bits/(Pixel*Frame)          : 0.018
Stream size                 : 4.26 GiB (81%)
Writing library             : x265 3.4+6-g73f96ff39:[Windows][GCC 11.0.0][64 bit] 10bit
Encoding settings           : cpuid=1111039 / frame-threads=5 / numa-pools=24 / wpp / no-pmode / no-pme / no-psnr / no-ssim / log-level=2 / input-csp=1 / input-res=3840x2020 / interlace=0 / total-frames=260585 / level-idc=51 / high-tier=1 / uhd-bd=0 / ref=3 / no-allow-non-conformance / repeat-headers / annexb / aud / hrd / info / hash=0 / no-temporal-layers / no-open-gop / min-keyint=24 / keyint=240 / gop-lookahead=0 / bframes=4 / b-adapt=2 / b-pyramid / bframe-bias=0 / rc-lookahead=25 / lookahead-slices=4 / scenecut=40 / hist-scenecut=0 / radl=0 / no-splice / no-intra-refresh / ctu=64 / min-cu-size=8 / no-rect / no-amp / max-tu-size=32 / tu-inter-depth=1 / tu-intra-depth=1 / limit-tu=0 / rdoq-level=2 / dynamic-rd=0.00 / no-ssim-rd / signhide / no-tskip / nr-intra=0 / nr-inter=0 / no-constrained-intra / no-strong-intra-smoothing / max-merge=3 / limit-refs=1 / limit-modes / me=1 / subme=3 / merange=57 / temporal-mvp / no-frame-dup / no-hme / weightp / no-weightb / no-analyze-src-pics / deblock=-3:-3 / no-sao / no-sao-non-deblock / rd=4 / selective-sao=0 / early-skip / rskip / no-fast-intra / no-tskip-fast / no-cu-lossless / b-intra / no-splitrd-skip / rdpenalty=0 / psy-rd=2.00 / psy-rdoq=0.00 / no-rd-refine / no-lossless / cbqpoffs=0 / crqpoffs=0 / rc=crf / crf=21.5 / qcomp=0.60 / qpstep=4 / stats-write=0 / stats-read=0 / vbv-maxrate=65000 / vbv-bufsize=55000 / vbv-init=0.9 / crf-max=0.0 / crf-min=0.0 / ipratio=1.40 / pbratio=1.30 / aq-mode=2 / aq-strength=1.00 / cutree / zone-count=0 / no-strict-cbr / qg-size=32 / no-rc-grain / qpmax=69 / qpmin=0 / no-const-vbv / sar=0 / overscan=0 / videoformat=5 / range=0 / colorprim=9 / transfer=16 / colormatrix=9 / chromaloc=1 / chromaloc-top=2 / chromaloc-bottom=2 / display-window=0 / master-display=G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(40000000,50) / cll=0,0 / min-luma=0 / max-luma=1023 / log2-max-poc-lsb=8 / vui-timing-info / vui-hrd-info / slices=1 / no-opt-qp-pps / no-opt-ref-list-length-pps / no-multi-pass-opt-rps / scenecut-bias=0.05 / hist-threshold=0.01 / no-opt-cu-delta-qp / no-aq-motion / hdr10 / no-hdr10-opt / no-dhdr10-opt / no-idr-recovery-sei / analysis-reuse-level=0 / analysis-save-reuse-level=0 / analysis-load-reuse-level=0 / scale-factor=0 / refine-intra=0 / refine-inter=0 / refine-mv=1 / refine-ctu-distortion=0 / no-limit-sao / ctu-info=0 / no-lowpass-dct / refine-analysis-type=0 / copy-pic=1 / max-ausize-factor=1.0 / no-dynamic-refine / no-single-sei / no-hevc-aq / no-svt / no-field / qp-adaptation-range=1.00 / no-scenecut-aware-qpconformance-window-offsets / right=0 / bottom=0 / decoder-max-rate=0
Default                     : Yes
Forced                      : No
Color range                 : Limited
Color primaries             : BT.2020
Transfer characteristics    : PQ
Matrix coefficients         : BT.2020 non-constant
Mastering display color pri : Display P3
Mastering display luminance : min: 0.0050 cd/m2, max: 4000 cd/m2

Here example subtitle

Untitled.ass