Google’s John Mueller said on Twitter that mobile intrusive interstitial elements won’t generally impact indexing but it can have a ranking impact. This goes back to the old Google Intrusive Interstitials Mobile penalty from 2016/2017.

John said “the intrusive interstitial element has a ranking effect, it wouldn’t affect indexing.”

This is in response to Lily Ray asking if Google would not index something because it may have triggered the mobile interstitial penalty? The answer was no. Here are those tweets:

The conversation does go on with more debugging:

So no, the Google mobile interstitial penalty does not impact Google indexing.

Forum discussion at Twitter.