Minus operator (-) does not work in rules (openHAB 4.2.0)

The minus operator (-) for subtraction does not work in rules in some cases since I updated from 4.1.3 to 4.2.0 Release Build.

Expected Behavior

The following code was working in 4.1.3:

    val sollflur = Temp_Soll_EG_Flur.state as Number

    val DateTime vor1Y = now.minusYears(1)

    val istdiele = Temp_Ist_EG_Diele.averageSince (vor1Y)
    val istflur = Temp_Ist_EG_Flur.averageSince (vor1Y)

    val solldiele = sollflur - (istflur - istdiele) // this is line 1543

Current Behavior

After I updated to 4.2.0, I am getting this error: 2024-07-08 14:13:57.877 [ERROR] [internal.handler.ScriptActionHandler] - Script execution of rule with UID 'main-40' failed: Unknown variable or command '-'; line 1543, column 30, length 18 in main

Possible Solution

My quick-fix was to add type Number to the variables:

    val Number istdiele = Temp_Ist_EG_Diele.averageSince    (vor1Y)
    val Number istflur  = Temp_Ist_EG_Flur.averageSince     (vor1Y)

But that does not solve the original issue.

Steps to Reproduce (for Bugs)

Put the lines above in a text file rule and save it as test.rules in the rules folder in your config folder. Watch the log file.

Context

I was trying to perfom the subtraction to calculate a derived value.

Your Environment

runtimeInfo:
  version: 4.2.0
  buildString: Release Build
locale: de-DE
systemInfo:
  configFolder: /etc/openhab
  userdataFolder: /var/lib/openhab
  logFolder: /var/log/openhab
  javaVersion: 17.0.11
  javaVendor: Debian
  osName: Linux
  osVersion: 6.6.31+rpt-rpi-2712
  osArchitecture: aarch64
  availableProcessors: 4
  freeMemory: 224180480
  totalMemory: 801112064
  uptime: 2694
  startLevel: 100
addons:
  - automation-jrubyscripting
  - automation-jsscripting
  - binding-astro
  - binding-exec
  - binding-fsinternetradio
  - binding-http
  - binding-knx
  - binding-lgwebos
  - binding-miio
  - binding-mqtt
  - binding-network
  - binding-tr064
  - misc-openhabcloud
  - persistence-rrd4j
  - transformation-jsonpath
  - transformation-map
  - transformation-regex
  - transformation-xslt
  - ui-basic
clientInfo:
  device:
    ios: false
    android: false
    androidChrome: false
    desktop: true
    iphone: false
    ipod: false
    ipad: false
    edge: false
    ie: false
    firefox: false
    macos: false
    windows: true
    cordova: false
    phonegap: false
    electron: false
    nwjs: false
    webView: false
    webview: false
    standalone: false
    os: windows
    pixelRatio: 1
    prefersColorScheme: dark
  isSecureContext: false
  locationbarVisible: true
  menubarVisible: true
  navigator:
    cookieEnabled: true
    deviceMemory: N/A
    hardwareConcurrency: 20
    language: de
    languages:
      - de
      - de-DE
      - en
      - en-GB
      - en-US
    onLine: true
    platform: Win32
  screen:
    width: 3440
    height: 1440
    colorDepth: 24
  support:
    touch: false
    pointerEvents: true
    observer: true
    passiveListener: true
    gestures: false
    intersectionObserver: true
  themeOptions:
    dark: dark
    filled: true
    pageTransitionAnimation: default
    bars: light
    homeNavbar: default
    homeBackground: default
    expandableCardAnimation: default
    blocklyRenderer: null
  userAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML,
    like Gecko) Chrome/126.0.0.0 Safari/537.36 Edg/126.0.0.0
timestamp: 2024-07-08T13:05:25.900Z

openhab / openhab-core