Vue version

@b775b71

Link to minimal reproduction

https://play.vuejs.org/#__DEV__eNqNVU2T2zYM/SuoerA9449k9+babtM2h+2hzaR7s/ZAS9CGWYlUScprj8f/vY+kLMmJk4kvFon3QBB4AE/Ju7qe7xtOlsnKZkbWjiy7pqZSqOd1mjibJptUyarWxtGJDBd0psLoikagjTrTH7qq2/35wi+8V5hT5Y4105/CCVrDQSG5zN8uyToj1fMvcX3362WDztsnT8q0so5ysIBtyduePSq0Hk1bMpaHw2FEZzB7HrZv8HbCDHiNyrmQivPAvbCl48qCh7uuvIvNOMQx6RFNjR1+aHHCHlVG4wmtN3RKFdFiQbKSDhAStaRMlKXf7mPzpFchHSl+pQ9ImrTcHmXY6nLP3hcK8Sgr1o0bR+etLYRzN5nS/Zs3E0RFMeL5XpQNiOGEVJ1TtVrEkqKAWABTl4gJK6LVrnFOK/otK2X2gkIProSKx1X0u1pEbOCdTm16zvAPN6Hsy5BPCy/bUcw0chy/7kZPaULLwIE9/AdFEX5dSPRzxmUJ+4nCJdoK0bmDApzLPe1nsgAsWtfrdXvK2xGAQojVAqCe0bnfz7i0fJt757kXCkg/zWb0UNAD5VwyuO6TtChdVbFyU6yY2BhtKNdsSWlHOssaQ7PZ0Mkg1nAhHLHb7b4Ib3FVka82VqGN8Hm1n0zRk1BSIZ/nn61WaNyguTRBjLUs2fxTOwmlpckyqtHboED9+lfYcwb5vexnnzh7ubH/2R78Xpp8gObY7HGBzuaEeWYXze///ZsP+O6Mlc6bEujvGD96FTc+xgj7HV2IsAe4EO1DmCsYCY/2/cGxspdL+UA98hzwSHDDPlHfunof7v38PvDQG8jiZUb5yXed91i8QhtUb+wVOyU5Iami8r2cX/joxdwL2dZCdZyoMOBjW/SEsB5K2pbQjxIVw+g7wEODXtpW2QZG6KDwdcPHtcyjwgXEDgiG4lcau9UXm+PxeAOI6YHwOm36K7a6jCq+omDZPh/feDgw5epHvART9JUfuT79WqGnvnhOUsWHQAFMNGX4H8LHobA1vNmuyDHP3ZLIPzlLemeMOGI6d2ev4huzfdq0UiOM1P8aaTjvZXURVjtVf8DrR860yVvnUzwqL0q/qs3wmPYyy/aV8G9cOOmiR0zxwbBOzv8Dp3V8Lw==

Steps to reproduce

1. Open the reproduction link
2. Click update items button in the PREVIEW area
3. You will see an error
4. Delete the comment on L26 in App.vue
5. Do step. 2 again
6. You will not see the error

What is expected?

No errors occur with or without comments

What is actually happening?

A comment in a template may cause an error under certain conditions

System Info

No response

Any additional comments?

No response

simple reproduction the root cause is: both slot fallback and slot nodes are stable fragments. should not take the fast path