I'm currently tracing around a similar problem and I found your question hoping for answers.
Data migration is magic but the magic isn't 100%
it sometimes lags when main Magento makes structural changes, creating wrong data
it sometimes misses that certain defaults have changed for data when it recreates it on migration, so every delta can ruin it
The above will not work for Magento 2.3.4. There are minor changes in the code and file path. You can read below to reduce the noise level for captcha images.
The functions to reduce the noise setDotNoiseLevel and setLineNoiseLevel are same but the code is moved in following file.
You can either change the ...