Page layout editor, properties panel layout problems

Description

There's some big problem or several problems with the Properties panel of the page layout editor.

There's no way to scroll and the items don't fit there.

This seems to be similar in Linux and Windows, 5.1 and 5.99. The screenshot is from 5.1.0 (but I tested with 5.1.6 on Windows, too).

KiCad Version

Application: PlEditor

Version: (5.99.0-2281-g2f31bf278), debug build

Libraries:
	wxWidgets 3.0.4
	libcurl/7.68.0 OpenSSL/1.1.1f zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh/0.9.3/openssl/zlib nghttp2/1.40.0 librtmp/2.3

Platform: Linux 5.4.0-40-generic x86_64, 64 bit, Little endian, wxGTK

Build Info:
	Date: Jul 12 2020 11:48:29
	wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
	Boost: 1.71.0
	OCE: 6.9.1
	Curl: 7.68.0
	Compiler: GCC 9.3.0 with C++ ABI 1013

Build settings:
	KICAD_SCRIPTING=ON
	KICAD_SCRIPTING_MODULES=ON
	KICAD_SCRIPTING_PYTHON3=ON
	KICAD_SCRIPTING_WXPYTHON=ON
	KICAD_SCRIPTING_WXPYTHON_PHOENIX=ON
	KICAD_SCRIPTING_ACTION_MENU=ON
	BUILD_GITHUB_PLUGIN=OFF
	KICAD_USE_OCE=ON
	KICAD_SPICE=OFF
	KICAD_STDLIB_DEBUG=OFF
	KICAD_STDLIB_LIGHT_DEBUG=OFF
	KICAD_SANITIZE=OFF