To remove diagonal taxiways you have to remove every single piece one by one, diagonal removal with CTRL key does not work.
====================
COLLECTED HARDWARE DATA
====================
Application version: Beta 5.0-7
Device
=====
Model: System Product Name (System manufacturer)
Operating system: Windows 10 (10.0.0) 64bit
RAM size: 65 GB
Battery status: Charging
Battery level: -1
Processor device
============
Type: AMD Ryzen 9 3900XT 12-Core Processor
Core count: 24
Frequency: 3 GHz
Grahpics device
===========
Vendor: NVIDIA
Type: NVIDIA GeForce RTX 3070
Memory size: 8 GB
Screen summary
===========
Full screen: True
Resolution: 1920 x 1080 @ 59Hz