Thanks for looking into this.
My Roon Core is hosted on a general use (i.e. not dedicated just to Roon) custom built Windows 10 PC, built around the following components:
Motherboard: ASUS Z170AR Motheboard
Processor: Intel Core i7 6700K Quad Core LGA 1151 4GHz Unlocked CPU
Memory: Corsair 64GB (4x16GB) CMK32GX4M2A2400C14 DDR4 2400MHz
Graphics: Gigabyte GeForce GTX 1070 G1 Gaming 8GB Video Card
Drive 1 (OS): Samsung 960 Pro Series 2TB M.2 SSD
Drive 2: Samsung 850 EVO 2TB SATAIII SSD Solid State Drive
Drive 3: Samsung 850 EVO 1TB SATAIII SSD Solid State Drive
Drive 4: Western Digital Red WD80EFZX 8TB 3.5" NAS Hard Drive
Drive 5: Western Digital Red WD80EFZX 8TB 3.5" NAS Hard Drive
Power Supply: eVGA 220G20750XR 750W G2 80+ Gold Full Modular Power Supply
OS: Microsoft Windows 10 Pro 64bit (currently on Version 1703, Build 15063.674)
My android device is a Samsung Galaxy S8+ on the Australian Telstra network, up to date with all over-the-air system updates provided on this carrier, with the following details:
Model number: SM-G955F
Android version: 7.0
Baseband version: G955FXXU1AQH3
Kernel version: 4.4.13-12050265
Build Number: NRD90M.G955FXXU1AQH3
Day to day I’m using an up-to-date version of SwiftKey Beta Keyboard version 220.127.116.11, which exhibits the problem described. However I just switched to an up-to-date version of SwiftKey Keyboard 18.104.22.168 (i.e. the non-beta version), and the problem is identical. I also tried using the default Samsung Keyboard that comes with the phone, and the problem was the same.
I should also note that on my system this problem is not intermittent - it happens deterministically every time the Roon app is opened and the “Navigation bar” is set to auto-hide using the Samsung Galaxy S8/S8+ “Show and hide button” on the navigation bar. On my phone this setting can be found at Settings > Display > Navigation bar > Show and hide button. It can be enabled by switching on that toggle, which adds a small dot to the left side of the soft navigation bar. Double tapping that dot when the Navigation Bar is showing on the screen will lock or unlock the Navigation Bar. When it is unlocked, it will slide down to disappear after a few seconds of not being used, like the old “auto-hide task bar feature on Windows”. This makes the foreground app take up the full screen on the Galaxy S8/S8+. You get the Navigation bar back by swiping up from the very bottom of the screen.
If the navigation bar is currently set to auto-hide, and you touch the “Search” text box in Roon, you see the SwitfKey keyboard slide up from the bottom of the screen for a second, flash, and then immediately disappear before you can use it. At this point, if you swipe up from the bottom of the screen to show the Navigation bar, then double tap the small circle on the left to lock it to “always show”, then hit the Roon search box again, the Swiftkey keyboard appears, stays visible, and can be used to enter a search term, as normal.
Hope that helps.