When converting my Sony A7IV compressed ARW files to DNG (for Lightroom 6.14 support) the "Interval" data is lost.

Note: I can provide a 61 MB ARW test file if you like.

--- System Information ---
OSX: 10.13.6 (17G13035)
Software: LRTimelapse
Version: 5.4 (2020-03-10)
Build: 619

--- Log snippet ---
[2020-06-08 00:02:45] INFO: Java version: 11.0.3 (64bit) from AdoptOpenJDK
[2020-06-08 00:02:45] INFO: Running on: Mac OS X locale: en_US
[2020-06-08 00:02:45] INFO: Found 8 processor cores.
[2020-06-08 00:02:45] INFO: Java runtime: 64 bit
[2020-06-08 00:02:47] DEBUG: Launching ExifTool: /usr/local/bin/exiftool
[2020-06-08 00:02:47] INFO: ExifTool: 11.38
[2020-06-08 00:02:47] DEBUG: Exif Tool available.
[2020-06-08 00:02:47] DEBUG: DNG Converter available.
[2020-06-08 00:02:47] DEBUG: MPEG Encoder available.
[2020-06-08 00:02:49] DEBUG: Using DNG Converter: /Applications/Adobe DNG Converter.app/Contents/MacOS/Adobe DNG Converter
[2020-06-08 00:02:50] DEBUG: Latest Version of Adobe DNG Converter: 12.2.0 (12020000) Installed Version: 12.2.1 (12020100)

There is a known bug in 5.4 if Sony cameras are set to specific timezones, this could happen. This will be fixed in the next update.
Here is a workaround, you could try:

Go to "Metadata / Shift capture Timestamps". Don't define any shift here, just leave everything on 0.
Enable "Overide original files", click on OK.
After the process finished, click on "Reload" in the workflow toolbar.

Let me know, if this brought up the intervals.

As a reminder: I don't recommend converting original files to DNG for timelapse work. It will just make the process slower. Whenever you can, work with the original ARW files instead.

Fixed in LRTimelapse 5.5.