Hello Vladimir @vzaytsev,
RFA 8.1.2.L1 is compatible with gcc 7.4. The comment that I find there is
"RFA C++ 8.1.2.L1 release is qualified using GCC 7.4.0 with C++17 Language Standard enabled"
Please note, in Operating System tab, the versions on Linux that the release was tested on.
If the memory issues suspected happen to manifest with a custom application, I would suggest testing a longer run with one of the examples that came with SDK for comparison, Consumer and Consumer_BatchView