First of all: I'm so sorry for all the trouble, please believe me this drove me crazy being so hard to narrow down the exact source of the issue. Also, I want to thank each and everyone of you for your patience and support in handling this, as it was the most difficult time WazzapMigrator went through in all these years.
On March 9th I was finally able to reproduce the issue affecting some random users having their WhatsApp crash a few days after import. This was related to the new WhatsApp Statuses, that weren't properly handled when imported from iPhone. So if you still hadn't received a WhatsApp Status on your iPhone, you were good to go. But if you had any, after a few days Android WhatsApp would start crashing.
HOW TO FIX THIS: please upgrade to WazzapMigrator 3.0.42 and perform migration from scratch (exactly as before, you can even use the same ChatStorage.sqlite). Then, when asked, reinstall WhatsApp accepting to restore from LOCAL backup (as already done the first time).
In order to be sure to restore from local backup, please check and disable WhatsApp Google Drive backups.