Unable to right-click inside application

[x10an14]

Hi!

I'm for some reason unable to right-click inside of Enpass (v5)!
(This worked for me earlier this month, a week or two ago).

This affects me in the following ways:

• No right-click menu appears when I right-click an item in the "middle column" (AKA the list).
• When I use the "pencil icon" to edit a selected item, I don't get the pop-up for the password generator.
• When I click the big '+' sign in the top-left corner, the drop-down list appears on the primary display, and not the display where Enpass is located.
• None of the drop-down/pop-out menus of "File, Edit, Item, View, etc." show at all when clicking them, or moving selection with arrowkeys.

[2018-08-07 12:18:19] 0 **I'M STRONGLY DISLIKING THE "NO CONTACTS" REGEX/FILTER RULE OF THIS FORUM**:~ $ lsb_release -a
No LSB modules are available.
Distributor ID:	LinuxMint
Description:	Linux Mint 19 Tara
Release:	19
Codename:	tara
[2018-08-07 12:32:12] 0 **I'M STRONGLY DISLIKING THE "NO CONTACTS" REGEX/FILTER RULE OF THIS FORUM**:~ $ uname -a
Linux jxq-Latitude-5590 4.15.0-30-generic #32-Ubuntu SMP Thu Jul 26 17:42:43 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
[2018-08-07 12:32:17] 0 **I'M STRONGLY DISLIKING THE "NO CONTACTS" REGEX/FILTER RULE OF THIS FORUM**:~ $ i3 --version
i3 version 4.14.1 (2017-09-24) © 2009 Michael Stapelberg and contributors
[2018-08-07 12:33:04] 0 **I'M STRONGLY DISLIKING THE "NO CONTACTS" REGEX/FILTER RULE OF THIS FORUM**:~ $ apt show enpass
Package: enpass
Version: 5.6.9
Priority: optional
Section: default
Maintainer: Sinew Software Systems Pvt Ltd. <**I'M STRONGLY DISLIKING THE "NO CONTACTS" REGEX/FILTER RULE OF THIS FORUM**>
Installed-Size: 87,2 MB
Depends: libxss1, lsof
Homepage: https://www.enpass.io/apps/linux/
License: SINEW END USER LICENSE AGREEMENT (EULA)
Vendor: Sinew Software Systems Pvt Ltd.
Download-Size: 36,1 MB
APT-Manual-Installed: yes
APT-Sources: http://repo.sinew.in stable/main amd64 Packages
Description: A cross-platform, complete password management solution that securely manages passwords and all other life important credentials like bank accounts, Credit cards, IDs, passport, driving licenses etc. Everything is saved locally on user's device and optionally he can sync through other devices using his accounts of Dropbox, Box, Google Drive, OneDrive and ownCloud.

N: There are 19 additional records. Please use the '-a' switch to see them.
[2018-08-07 12:35:43] 0 **I'M STRONGLY DISLIKING THE "NO CONTACTS" REGEX/FILTER RULE OF THIS FORUM**:~ $

Anyone have any tips or ideas? Right-clicking works fine in Firefox, Sublime, gnome-terminal, and Spotify.
I've got a suspicion this might be QT related? Since I read somewhere that Enpass uses QT? Anyone got any suggestions on how to confirm this?

Thanks for your time and interest in helping!