New Monitors

Hey guys, I purchased my DS build back in January. Here is the build..

System Configuration:

Chassis Model: Digital Storm Lumos
Exterior Finish: - Standard Factory Finish
Trim Accents: - Standard Factory Finish
Processor: AMD Ryzen 5 2600X (6-Core) (Boost Up to 4.2 GHz)
Motherboard: ASUS / MSI (AMD B350M Chipset) (Up to 2x PCI-E Devices)
System Memory: 16GB DDR4 3000MHz Corsair Vengeance RGB Pro (RGB Light Bar)
Power Supply: 600W Digital Storm Performance Series (Supports up to an NVIDIA RTX 2070 GPU)
Expansion Bay: - No Thanks
Optical Drive: - No Thanks
Storage Set 1: 1x SSD (500GB Digital Storm Performance Series)
Storage Set 2: 1x Storage (2TB Seagate / Toshiba)
Storage Set 3: - No Thanks
RAID Config: - No Thanks
RAID Card: - No Thanks
Internet Access: High Speed Network Port (Supports High-Speed Cable / DSL / Network Connections)
Graphics Card(s): 1x GeForce GTX 1070 8GB (VR Ready)
Sound Card: Integrated Motherboard Audio
HPC Processor: - No Thanks
Extreme Cooling: H20: Stage 1: Digital Storm Vortex 120mm Liquid CPU Cooler (Fully Sealed + No Maintenance)
HydroLux Tubing Style: - Not Applicable, I do not have a custom HydroLux liquid cooling system selected
HydroLux Fluid Color: - Not Applicable, I do not have a custom HydroLux liquid cooling system selected
Cable Management: Exotic Cable Management - White - (Cable Combs with Custom Color Sleeved Extension Cables)
Chassis Fans: Corsair LL Series (RGB Fans) (Software Controlled Effects)
Internal Lighting: Remote Controlled Advanced LED Lighting System (Multiple RGB Color Modes)
Airflow Control: - No Thanks
Chassis Mods: - No Thanks
Noise Reduction: - No Thanks
LaserMark: Option Not Available
CPU Boost: Stock Factory Turbo Boost Advanced Automatic Overclocking
Graphics Boost: Yes, Overclock the video card(s) as much as possible with complete stability
OS Boost: - No Thanks, Please do not tweak the services on the operating system
Operating System: Microsoft Windows 10 Home (64-Bit Edition)
Recovery Tools: USB Drive - Windows 10 Installation (Format and Clean Install)
Virus Protection: Windows Defender Antivirus (Built-in to Windows 10)
Office: - No Thanks
Game: - No Thanks
Display: - No Thanks
Surge Shield: - No Thanks
Speakers: - No Thanks
Keyboard: - No Thanks
Mouse: - No Thanks
Branded Gear: - No Thanks
Priority Build: - No Thanks, Ship Within 20-25 Business Days After Order Is Successfully Processed
Warranty: Life-time Expert Care with 3 Year Limited Warranty (3 Year Labor & 1 Year Part Replacement)

So I recently upgraded my monitors to two Samsung U28E510 monitors. I have one of them connected through HDMI (this one is working fine) and the other I have HDMI from the monitor to a HDMI -> Display Port adapter since the 1070 doesn't have a second HDMI input. On the first monitor HDMI -> HDMI I am able to run 3840 x 2160 without issue. However, on the second one I am being capped at 1920 x 1080. Is my video card not capable of running both screens at that resolution, or is this a connector issue?