How to reproduce:
1. Open attached project (1223809.zip)
2. Enter Play Mode
3. Observe the sprites in the Game window

Expected result: There are clearly visible white square sprites
Actual result: The square sprites are rendered in black (on Linux) or not rendered at all (on Windows)

Reproducible with: 2019.3.6f1, 2020.1.0b2, 2020.2.0a4
Could not test with: 2017.4.38f1, 2018.4.19f1, 2019.2.21f1 (doesn't have a "Reload Scene" option)

Notes:
1. For the bug to reproduce these conditions have to be met:
a. The "Reload Scene" setting under "Enter Play Mode Settings" (in Project Settings > Editor) has to be disabled
b. "Sprite Packer" mode has to be set to "Always Enabled" or "Sprite Atlas V1 - Always Enabled" for versions 2020.1.x and newer
c. Sprites used in the Tilemap have to be packed in a Sprite Atlas
d. The Tilemap palette has to have at least 2 sprites
2. Tested on Windows 7 and Linux (KDE Neon 5.18 and Ubuntu 18.04)