bug(mac): Word online in Chrome/Safari does not work correctly at beginning of paragraph

**Describe the bug**
Word Online in Chrome and Safari will not replace context correctly at the beginning of a paragraph. It does however work correctly elsewhere in the paragraph. This may be a race condition (in Safari there is some unreliability elsewhere in the paragraph also).

This issue does not arise with Firefox. In Firefox, Word Online appears to work 100% correctly.

**To Reproduce**
Steps to reproduce the behavior:
1. Open office.com and start a new document
2. With the GFF Amharic keyboard, type ta
3. The document is left blank, on Chrome. On Safari, ትታ is the result.

**Expected behavior**
The initial ት letter should be converted to ታ.

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**Keyman for macOS:**
- OS: macOS Catalina
- Keyman version: 14.0.190
- Target Application: Chrome 87.0.4280.67 or Safari 14.0.1 (16610.2.11.51.8), with Word Online 16.0.13518.41000

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**Keyboard**
- Keyboard name: gff_amharic
- Keyboard version: 1.9.2
- Language name: Amharic