InnerBlocks block rendering issue at Gutenberg

I’m trying to use the block

<InnerBlocks />

Settings Screenshot https://prnt.sc/BTxTQ9Tcmg_W

I used to have in HTML + Handlebars:

<a href="{{tt-anchor}}">
  tt-inner-block
</a>

It used to work fine in Gutenberg and the frontend. Since the deprecation of the control I converted this to:

<a href="{{tt-anchor}}">
  <InnerBlocks />
</a>

I still get the the desired html output at the frontend (for the existing blocks) but it seems that I can’t create or edit the current blocks in Gutenberg anymore. When I click on a block to modify the anchor I get an error: “This block has encountered an error and cannot be previewed.“