I also noticed that Steam swore at pressure-vessel-wrap[449]: W: Disabling gtk3-nocsd LD_PRELOAD: it is known to cause crashes., so I've try to remove this:

sudo apt purge gtk3-nocsd libgtk3-nocsd0:amd64 libgtk3-nocsd0:i386 -y

But it also doesn't helped me 😟:

chdir "/mnt/Games/Steam/steamapps/common/Mega Serval"
ERROR: ld.so: object '/home/user/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Game Recording - would start recording game 2009720, but recording for this game is disabled
Adding process 5139 for gameID 2009720
ERROR: ld.so: object '/home/user/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/home/user/.local/share/Steam/ubuntu12_64/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS64): ignored.
ERROR: ld.so: object '/home/user/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/home/user/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Adding process 5140 for gameID 2009720
Adding process 5141 for gameID 2009720
Adding process 5142 for gameID 2009720
setlocale "en_US.UTF-8": No such file or directory
pv-locale-gen: Missing locale en_US.UTF-8
pv-locale-gen: Generating locale ru_RU.UTF-8...
pv-locale-gen: Generated locale ru_RU.UTF-8 successfully
pv-locale-gen: Generating locale en_US.UTF-8...
pv-locale-gen: Generated locale en_US.UTF-8 successfully
pv-adverb[5694]: W: Container startup will be faster if missing locales are created at OS level
Adding process 5739 for gameID 2009720
Adding process 5742 for gameID 2009720
Adding process 6181 for gameID 2009720
fsync: up and running.
wine: RLIMIT_NICE is <= 20, unable to use setpriority safely
Adding process 6182 for gameID 2009720
Adding process 6185 for gameID 2009720
Adding process 6187 for gameID 2009720
Adding process 6190 for gameID 2009720
Adding process 6199 for gameID 2009720
Adding process 6212 for gameID 2009720
Adding process 6218 for gameID 2009720
Adding process 6231 for gameID 2009720
Setting breakpad minidump AppID = 2009720
Steam_SetMinidumpSteamID:  Caching Steam ID:  76561198248711762 [API loaded no]
Adding process 6249 for gameID 2009720
pid 6183 != 6182, skipping destruction (fork without exec?)
Game Recording - game stopped [gameid=2009720]
Removing process 6249 for gameID 2009720
Removing process 6231 for gameID 2009720
Removing process 6218 for gameID 2009720
Removing process 6212 for gameID 2009720
Removing process 6199 for gameID 2009720
Removing process 6190 for gameID 2009720
Removing process 6187 for gameID 2009720
Removing process 6185 for gameID 2009720
Removing process 6182 for gameID 2009720
Removing process 6181 for gameID 2009720
Removing process 5742 for gameID 2009720
Removing process 5739 for gameID 2009720
Removing process 5142 for gameID 2009720
Removing process 5141 for gameID 2009720
Removing process 5140 for gameID 2009720
Removing process 5139 for gameID 2009720