After convert 8.3->9.1, hexrays stack type are lost

IDA General Bugs
1

idb 8.3
in hexrays i set type of var std_string (this my struct size of 0x20)
but when press ENTER in hexrays view on this name of type
i see

-0000000000000098 var_98 ymmword ?
-0000000000000078 var_78 ymmword ?
-0000000000000058 var_58 ymmword ?
-0000000000000038 var_38 ymmword ?

in hexrays 8.3 all ok

but after convert idb 8.3 to idb 9.1
both types on stack and in hexrays became as __m256

-0000000000000098 __m256 var_98;
-0000000000000078 __m256 var_78;
-0000000000000058 __m256 var_58;
-0000000000000038 __m256 var_38;

after conversion, hexrays stack types were lost
but not all
but only some
I suppose only those that were not tied to the ida stack

you yourself made it so that in the flight you can set the type separately from the ida stack

this functionality is poorly developed in the conversion idb

2

IDA 9 does not support legacy asm-style structures, so they have to be converted to new type system during upgrade. The decompiler-specific type storage is no longer used so in case of conflicts stack frame members are taken from IDA.

3

so in IDA 9 all hexrays stack vars = ida stack vars
rights ?
its interesting how about cases when

hexrays stack vars != ida stack vars

as far as I remember it was introduced for complex cases
and I had such cases
unfortunately I can’t remember them right now
to check what will happen in pseudocode

4

There are still cases where the decompiler keeps additional information about local stack variables, such as split or mapped variables, but in most cases the stack frame type info is now shared between IDA and the decompiler.

5

does this have anything to do with it?

Type info leak has been detected and fixed (refcnt=1; idx=50584)
Type info leak has been detected and fixed (refcnt=1; idx=50637)
Type info leak has been detected and fixed (refcnt=1; idx=50640)
Type info leak has been detected and fixed (refcnt=1; idx=50653)
Type info leak has been detected and fixed (refcnt=1; idx=50779)
Type info leak has been detected and fixed (refcnt=1; idx=50784)
6

Probably not; this message usually indicates an issue in IDA or some plugin/script.