Upgrading to version 1.7 does not render component

Question

We have a Sitecore 9.0 instance with an SXA version 1.5 and recently we created a new instance of Sitecore 9.0.1 with SXA 1.7. We have all our contents serialized through Unicorn and when we synced the items to the new Sitecore instance the components were not rendered. However, the components are in the presentation details.

Is this a bug from SXA or are there some compatibility issues with 1.5 and 1.7?

EDIT: I saw in the 1.7 change logs that

"Dynamic Placeholder enabled components now have a default placeholder settings item to fall back on if a specific item was not created."

Upon checking, my components in 1.7 have this item property called Dynamic Placeholder ID (values automatically generated by SXA, most likely?), whereas it doesn't exist in 1.5. Components with this settings is not rendered while components that doesn't have that property (such as the Rich Text component) are rendered into the page. Hoping this could shed light on my issue.

Answer 1

That is not how you should upgrade. You have written that:

"We have all our contents serialized through Unicorn and when we synced the items to the new Sitecore instance the components were not rendered."

This means (if I understand this correctly) that SXA upgrade manager had no chance to upgrade your content as it was not there. You should install a new version of SXA in the instance where whole content exist. If we introduced a change which can break your content then for sure there is an upgrade step which will migrate your content. Even if you run upgrade steps and thehaveas been successful then there was no content. For me, it looks like you have updated instance (to 1.7) but with old not upgraded content.