Unable to create any visible signature trace using Swipe function iOS

Appium to 1.6.5
Xcode 8.3.2
iOS 10.3.1

Signature imitation using Swipe used to work for me in Appium 1.5/XCode 7.
Now Appium is updated to 1.6.5 and Xcode to 8.3.2.
Swipe is working normally (with offsets and such) but it leaves no traces on Signature element.
I tried everything - Swipe is definitely try to start movement within Signature active area but there are not traces.
In fact, if I manually draw visible line in Signature element BEFORE automated Swipe action then it ERACES manual line.

Log example of normal vertical Swipe action (yet no visible signature trace)

[XCUITest] Found matching gesture: drag
[JSONWP Proxy] Proxying [POST /wda/dragfromtoforduration] to [POST http://localhost:8100/session/3ECDD413-E580-4B99-B628-53E8350A676D/wda/dragfromtoforduration] with body: {“fromX”:200,“fromY”:250,“toX”:200,“toY”:220,“duration”:1}
[JSONWP Proxy] Got response with status 200: {“sessionId”:“3ECDD413-E580-4B99-B628-53E8350A676D”,“value”:{},“status”:0}
[MJSONWP] Responding to client with driver.performTouch() result: null
[HTTP] <-- POST /wd/hub/session/79e27b60-37e7-4710-b33d-c903a4c74f2a/touch/perform 200 6134 ms - 76
[HTTP] --> POST /wd/hub/session/79e27b60-37e7-4710-b33d-c903a4c74f2a/touch/perform {“sessionId”:“79e27b60-37e7-4710-b33d-c903a4c74f2a”,“actions”:[{“action”:“press”,“options”:{“y”:“350”,“x”:“300”}},{“action”:“wait”,“options”:{“ms”:“1000”}},{“action”:“moveTo”,“options”:{“y”:"-30",“x”:“0”}},{“action”:“release”,“options”:{}}]}
[MJSONWP] Calling AppiumDriver.performTouch() with args: [[{“action”:“press”,“options”:{“y”:“350”,“x”:“300”}},{“action”:“wait”,“options”:{“ms”:“1000”}},{“action”:“moveTo”,“options”:{“y”:"-30",“x”:“0”}},{“action”:“release”,“options”:{}}],“79e27b60-37e7-4710-b33d-c903a4c74f2a”]
[XCUITest] Executing command ‘performTouch’
[XCUITest] Received the following touch action: press(options={“y”:“350”,“x”:“300”})-wait(options={“ms”:“1000”})-moveTo(options={“y”:"-30",“x”:“0”})-release(options={})