I am experiencing an ongoing issue when exporting videos from After Effects and uploading them to TikTok

I am experiencing an ongoing issue when exporting videos from After Effects and uploading them to TikTok, and I would appreciate your assistance.

I am using Adobe Media Encoder to export my videos with the following settings:

• Format: H.264
• Profile: High
• Level: 4.2
• Bitrate:
  • VBR, 2 Pass
  • Target: 8–12 Mbps
•  

After exporting, the video appears in very high quality when first uploaded to TikTok. However, after several hours, the video quality drops significantly, as if the video is being heavily recompressed.

My questions are:

• Are there any Adobe-recommended export settings specifically optimized for TikTok to minimize quality loss after upload?
• Is there any technical reason related to exporting from After Effects or Adobe Media Encoder that could cause this noticeable drop in quality over time?

I would appreciate your guidance on the best possible export settings from After Effects to achieve stable and high-quality results on TikTok.