Steps to reproduce:
1. Open QA-supplied project ("1220085 Bug Repo.zip")
2. Build and run
3. Inspect the Profiler -> CPU Usage

Expected: The Main Thread -> Gfx.WaitFor* (+2019.3 -> Semaphore.WaitForSignal) marker is correlated with the Gfx.WaitForThread marker in the Render Thread
Actual: The Render Thread sits empty while Gfx.WaitFor* / Semaphore.WaitForSignal is active

Versions:
Repro on: 2019.3.0a3, 2019.3.6f1, 2019.3.14f1
No repro on: 2018.4.23f1(No Semaphore.WaitForSignal present), 2019.3.0a1 (Can't build), 2019.3.0a2 (Can't build), 2020.1.0b9, 2020.2.0a11

Repro on:
Vulkan:
VLNQA00021, Samsung Galaxy S7 (SM-G930F), Android 8.0.0, CPU: Exynos 8 Octa 8890, GPU: Mali-T880
N/A, Samsung Galaxy S9 (SM-G960F), Android 8.0.0, CPU: Exynos 9 Series 9810, GPU: Mali-G72

No repro on:
Vulkan:
VLNQA00121, Samsung Galaxy S9 (SM-G960F), Android 9, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00288, Samsung Galaxy J7 (SM-J730F), Android 8.1.0, CPU: Exynos 7 Octa 7870, GPU: Mali-T830
VLNQA00277, Asus ROG Phone (ASUS_Z01QD), Android 8.1.0, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630
VLNQA00001, Google Pixel 2 (Pixel 2), Android 9, CPU: Snapdragon 835 MSM8998, GPU: Adreno (TM) 540
VLNQA00128, Samsung Galaxy Note8 (SM-N950F), Android 9, CPU: Exynos 9 Octa 8895, GPU: Mali-G71

OpenGLES3:
VLNQA00021, Samsung Galaxy S7 (SM-G930F), Android 8.0.0, CPU: Exynos 8 Octa 8890, GPU: Mali-T880
VLNQA00277, Asus ROG Phone (ASUS_Z01QD), Android 8.1.0, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630
VLNQA00121, Samsung Galaxy S9 (SM-G960F), Android 9, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00288, Samsung Galaxy J7 (SM-J730F), Android 8.1.0, CPU: Exynos 7 Octa 7870, GPU: Mali-T830
N/A, Samsung Galaxy S9 (SM-G960F), Android 8.0.0, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00313, Huawei Y6 Ⅱ Compact (HUAWEI LYO-L01), Android 5.1, CPU: MediaTek MT6735, GPU: Mali-T720
VLNQA00140, Samsung Galaxy S4 (GT-I9505), Android 5.0.1, CPU: Snapdragon S4 Plus MSM8960, GPU: Adreno (TM) 320
VLNQA00013, Samsung Galaxy S6 edge+ (SM-G928F), Android 7.0, CPU: Exynos 7 Octa 7420, GPU: Mali-T760
VLNQA00001, Google Pixel 2 (Pixel 2), Android 9, CPU: Snapdragon 835 MSM8998, GPU: Adreno (TM) 540
VLNQA00078, Motorola Nexus 6 (Nexus 6), Android 7.1.1, CPU: Snapdragon 805 APQ8084AB, GPU: Adreno (TM) 420
VLNQA00128, Samsung Galaxy Note8 (SM-N950F), Android 9, CPU: Exynos 9 Octa 8895, GPU: Mali-G71

OpenGLES2:
VLNQA00021, Samsung Galaxy S7 (SM-G930F), Android 8.0.0, CPU: Exynos 8 Octa 8890, GPU: Mali-T880
VLNQA00277, Asus ROG Phone (ASUS_Z01QD), Android 8.1.0, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630
VLNQA00121, Samsung Galaxy S9 (SM-G960F), Android 9, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00288, Samsung Galaxy J7 (SM-J730F), Android 8.1.0, CPU: Exynos 7 Octa 7870, GPU: Mali-T830
N/A, Samsung Galaxy S9 (SM-G960F), Android 8.0.0, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00313, Huawei Y6 Ⅱ Compact (HUAWEI LYO-L01), Android 5.1, CPU: MediaTek MT6735, GPU: Mali-T720
VLNQA00140, Samsung Galaxy S4 (GT-I9505), Android 5.0.1, CPU: Snapdragon S4 Plus MSM8960, GPU: Adreno (TM) 320
VLNQA00013, Samsung Galaxy S6 edge+ (SM-G928F), Android 7.0, CPU: Exynos 7 Octa 7420, GPU: Mali-T760
VLNQA00001, Google Pixel 2 (Pixel 2), Android 9, CPU: Snapdragon 835 MSM8998, GPU: Adreno (TM) 540
VLNQA00078, Motorola Nexus 6 (Nexus 6), Android 7.1.1, CPU: Snapdragon 805 APQ8084AB, GPU: Adreno (TM) 420
VLNQA00128, Samsung Galaxy Note8 (SM-N950F), Android 9, CPU: Exynos 9 Octa 8895, GPU: Mali-G71