Unusual GL_FRAMEBUFFER INCOMPLETE ATTACHMENT Error using JavaFX version greater than 12

Hi All,
I have built a LINUX based UBUNTU snap app using BASE20 (i.e. Ubuntu 20.04) as a target OS, and it is in distribution.

That App works perfectly well using OpenJDK 11 through to 15.0.1 on OpenJFX 11 and 12. However if I move to a more recent version of OpenJFX I get the following error for every screen change (a change of scene on a stage) - the screen goes blank and the following error is displayed on the terminal:

Incomplete attachment. (GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT)(FBO - 820)
Error creating framebuffer object with TexID 1).

If I force a screen re-write (e.g. by switching to a terminal window or another app, then back to my app) the screen then displays the expected contents.

This seems there may be a bug in successive JAVAFX releases - however it is possible that something is missing in the UBUNTU 20.04 libraries incorporated in the snap. I should point out that it fails in the same way even when being run in the development environment or as a stand alone program.

My dev environment is IntelliJ Idea using gradle with openJDK 15.

my snapcraft.yaml

name: photonotebook
title: PhotoNoteBook
version: "1.4.1"
summary: A digital photography library manager and notebook 
license: Proprietary
description: PhotoNoteBook is a digital photograph library manager enabling collections of images and the making of notes and memo's for the collections and the photographs. 
icon: photonotebook.png 

confinement: strict
grade: stable
base: core20 

 
apps:
  photonotebook:
    command: bin/photonotebook
    command-chain: [bin/desktop-launch]
    
    plugs: [home, unity7,  opengl, network, removable-media, optical-drive ,desktop, desktop-legacy, gsettings, x11, wayland]
     
parts:
  photonotebook:
    plugin: dump
    source: ./photonotebook/
    stage-packages: [libgif7, libx11-6, libxext6, libxi6, libxrender1, libxtst6, libasound2, libjpeg8, liblcms2-2, libfreetype6, libpng16-16, libcanberra-gtk-module]

  desktop-gtk3:
    source: https://github.com/ubuntu/snapcraft-desktop-helpers.git
    source-type: git
    source-subdir: gtk
    plugin: make
    make-parameters: ["FLAVOR=gtk3"]
    build-packages:
      - libgtk-3-dev
    stage-packages:
      - libxkbcommon0  # XKB_CONFIG_ROOT
      - ttf-ubuntu-font-family
      - dmz-cursor-theme
      - light-themes
      - adwaita-icon-theme
      - gnome-themes-standard
      - shared-mime-info
      - libgtk-3-0
      - libgdk-pixbuf2.0-0
      - libglib2.0-bin
      - libgtk-3-bin
      - unity-gtk3-module
      - libappindicator3-1
      - locales-all
      - xdg-user-dirs
      - ibus-gtk3
      - libibus-1.0-5
      - fontconfig-config # start of my additions
      - fonts-liberation
      - ttf-dejavu-core
      - hicolor-icon-theme
      - libgtk2.0-0
      - libcanberra-gtk-module
      - libcanberra-gtk0
      - libcanberra0 

Thanks in advance

Alan

I have subsequently reported this as a potential bug and I am awaiting a response and a bug report number. I will update as this could be a difficult issue for JAVAFX based snap development.