When experiencing bugs with the xfce4-power-manager component, your way of helping things getting fixed is to report a bug about it in bugzilla.
Note: For this you will need to have/create an account.

• [Bug 15964] When the `low battery` warning is displayed, and then the laptop is plugged in to power, the message should disappear (2019/09/24 01:03)
• [Bug 15941] org.freedesktop.PowerManagement.Inhibit should not inhibit screensaver locking (2019/09/09 02:07)
• [Bug 15926] it wont turn off my display! (2019/09/04 18:51)
• [Bug 15910] [Patch] Fix 'cast between incompatible function types' warnings (2019/09/01 19:57)
• [Bug 11339] Add support for logind hybrid sleep when closing lid (2019/08/26 16:59)
• [Bug 15805] [feature-request] Show time elapsed on battery since last AC disconnect (2019/08/11 21:17)
• [Bug 15773] Add indicator that Presentation Mode is active (2019/08/02 20:03)
• [Bug 15764] Laptop does not suspend after power is unplugged (2019/07/30 16:11)
• [Bug 15180] screen remains blank on any activity (2019/07/29 22:30)
• [Bug 15761] Confusing magic integer value "9" for timeout "never". (2019/07/29 21:53)
• [Bug 12755] Battery charging/full charged notification spamming (2019/07/19 19:26)
• [Bug 15683] Lowest brightness is 0 (black screen) (2019/07/06 21:01)
• [Bug 15151] Unable to override logind lid open/close handlers (2019/07/03 12:00)
• [Bug 15197] [patch] xfpm-backlight-helper reads wrong file for brightness (2019/07/01 00:36)
• [Bug 15658] Standby with lockscreen resume : no lock screen, screen stay black, power button shutdowns computer (2019/06/30 16:01)
• [Bug 12062] Screen brightness - increase number of increments (2019/06/19 16:21)
• [Bug 15483] Exhausted battery caused freezing (2019/06/17 01:35)
• [Bug 15470] xfce4-power-manager - notifications timeout is hardcoded / not managed by xfce4-notifyd (2019/05/29 03:22)
• [Bug 15486] [Suggestion] Add support for suspend when swap is turned off, but the partition given in the kernel command line. (2019/05/28 04:53)
• [Bug 15300] Laptop lid action not respected (2019/05/27 21:57)

If your bug has not been reported before, please submit a new bug report. Please ensure that you disclose any information that might be relevant for developers reading the bugreport, e.g. what distribution you're using, what package-version of xfce4-power-manager or related Xfce libraries etc. When writing your bug report, try to be as descriptive as possible, but avoid verbosity; Mozilla has a nice guide on how to write a bug report.

For more information, see Bug Reporting and Fixing.