When I select multiple HEIC files in Lr Classic 10.3 and choose Edit In>Open as Layers in Photoshop I notice that Photoshop (22.4.2) opens but the HEIC files don't appear in Photoshop. However, doing the same with other file formats (raw, TIF, jpeg) works as expected. Including even a single HEIC file among other file types selected will not allow the Lightroom Edit In>Open as Layers in Photoshop to function as expected (no files appear in Photoshop).
When I select the same HEIC files in Bridge and choose Tools>Photoshop>Load files into Photoshop as Layers I get the expected result.
Lightroom Classic version: 10.3 [ 202105281559-8dc50eb4 ] License: Creative Cloud Language setting: en Operating system: Windows 10 - Home Premium Edition Version: 10.0.19041 Application architecture: x64 System architecture: x64 Logical processor count: 12 Processor speed: 3.1GHz SqLite Version: 3.34.0 Built-in memory: 16191.3 MB Real memory available to Lightroom: 16191.3 MB Real memory used by Lightroom: 1340.6 MB (8.2%) Virtual memory used by Lightroom: 1923.4 MB
Adobe Photoshop Version: 22.4.2 20210602.r.242 a4f6042 x64 Number of Launches: 98 Operating System: Windows 10 64-bit Version: 10 or greater 10.0.19041.1023 System architecture: Intel CPU Family:6, Model:14, Stepping:10 with MMX, SSE Integer, SSE FP, SSE2, SSE3, SSE4.1, SSE4.2, AVX, AVX2, HyperThreading Physical processor count: 6 Logical processor count: 12 Processor speed: 3192 MHz Built-in memory: 16191 MB Free memory: 10368 MB Memory available to Photoshop: 11929 MB Memory used by Photoshop: 70 %