Your Eevee-rendered 3D model flickers mainly due to insufficient anti-aliasing, glitchy screen space effects (e.g., SSAO/SSR), or inconsistent mesh normals.
Insufficient anti-aliasing leaves unsmoothed "jaggies" that flicker when the camera or model moves. Screen space effects rely on nearby pixels—thin or overlapping geometry makes them glitch. Inconsistent normals (flipped/messy) confuse Eevee’s lighting, causing flickering patches.
Fix it by increasing anti-aliasing samples (Render Settings > Anti-Aliasing), disabling screen space effects temporarily to test, or recalculating normals (select model > Mesh > Normals > Recalculate Outside).