Earth patches not removed when building tiles on top

Bui;t a runway in the wrong spot so i erased it. After replacing the run way i was trying to add taxiways but where the old runway was it would allow me to build the taxi way it just wouldnt show it.

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COLLECTED HARDWARE DATA
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Application version: Beta 4.2-0

Device
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Model: MS-7A72 (MSI)

Operating system: Windows 10 (10.0.0) 64bit

RAM size: 16 GB

Battery status: Charging
Battery level: -1

Processor device
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Type: Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz
Core count: 8
Frequency: 4 GHz

Grahpics device
===========

Vendor: NVIDIA
Type: NVIDIA GeForce GTX 1080
Memory size: 8 GB

Screen summary
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Full screen: True
Resolution: 1920 x 1080 @ 60Hz