On 18.04 if you change setting it will result in a stable transparent background:
1. Uncheck "Use transparency from system theme" 2. "Check Use tranparent background" 3. Re-check "Use transparency from system theme"
Also reported at bug #1726262
On 18.04 if you change setting it will result in a stable transparent background:
1. Uncheck "Use transparency from system theme"
2. "Check Use tranparent background"
3. Re-check "Use transparency from system theme"
Also reported at bug #1726262