Warped steams seam to glitch when placed in water ( maybe just flowing water) and appear to place but do not use up the block in inventory. Then disappear when updated. Player can then not interact with other blocks when holding warped stems. Work around is to mine new warped blocks.
Thank you for your report!
We're actually already tracking this issue at MCPE-65522, so I resolved and linked this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
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