Yes Steve Model appears to have an incompatibility with this Crawl mod.
Using only YSM and the Crawl mod, nothing else. The issue appears to stem from the animations themselves; however, toggling the "Replace Crawl Animation" config has no effect, it still breaks the functionality.
Having the Crawl mod installed alongside YSM also seems to have an affect on "vanilla" crawling behavior, see the following screenshots...
YSM with Crawl mod installed:

YSM without Crawl mod installed:

If it matters, I'm using Minecraft version 1.21.1. This behavior appears to be platform-independent, happening on both Fabric and NeoForge.
Yes Steve Model appears to have an incompatibility with this Crawl mod.
Using only YSM and the Crawl mod, nothing else. The issue appears to stem from the animations themselves; however, toggling the "Replace Crawl Animation" config has no effect, it still breaks the functionality.
Having the Crawl mod installed alongside YSM also seems to have an affect on "vanilla" crawling behavior, see the following screenshots...
YSM with Crawl mod installed:

YSM without Crawl mod installed:

If it matters, I'm using Minecraft version 1.21.1. This behavior appears to be platform-independent, happening on both Fabric and NeoForge.