How to reproduce:
1. Open the attached project (case-1261524.zip)
2. In the Project window select the 'test' ScriptableObject
3. In the Inspector window expand the Strings field and set Element 1 to ':one'
4. Exit and reopen Unity
5. Select 'test' ScriptableObject again

Expected result: the field 'Strings' remains unchanged
Actual result: all the Elements starting with a colon symbol got removed and an Element before them got set to an empty string (size = '2', Element 0 = '', Element 1 = 'two')

Reproducible with: 2019.3.0a1, 2019.4.3f1, 2020.1.0b15, 2020.2.0a17
Not reproducible with: 2018.4.24f1, 2019.2.0b10, 2019.2.21f1

Notes:
1. The issue doesn't occur when a colon is not the first symbol of a string
2. The issue occurs only with an array of strings (not with char, char[], string)
3. The issue also occurs when a Script with string array field is used as a Component to a GameObject