'struct.error: unpack requires a buffer of 4 bytes' within SpatialIndexMediator in case of various parallel database accesses

The SpatialIndexMediator crashes with the exception below if many database queries are executed in parallel (here, GMS was running on 32 CPUs):

2020/11/25 22:33:34 [9290467]:   Generating DEM...
2020/11/25 22:33:34 [13512282]:   Generating DEM...
2020/11/25 22:33:34 [9290467]:   Acquired lock 'DatabaseLock', slot #1.
2020/11/25 22:33:34 [9290467]:   Released lock 'DatabaseLock', slot #1.
2020/11/25 22:33:34 [9290467]:   A static elevation is assumed during atmospheric correction due to an error during creation of the DEM corresponding to scene 9290467 (entity ID: LT50460322008283PAC01). Error message was: 
error('unpack requires a buffer of 4 bytes')

2020/11/25 22:33:34 [9290467]:   Print traceback in case you care:
2020/11/25 22:33:34 [9290467]:   Traceback (most recent call last):
  File "/home/gfz-fe/scheffler/python/gms_preprocessing/gms_preprocessing/algorithms/L1C_P.py", line 689, in _get_dem
    dem = inObj4dem.dem[:].astype(np.float32)
  File "/home/gfz-fe/scheffler/python/gms_preprocessing/gms_preprocessing/model/gms_object.py", line 551, in dem
    self._dem = DC.from_extent(*DC_args)
  File "/home/gfz-fe/scheffler/python/gms_preprocessing/gms_preprocessing/io/input_reader.py", line 476, in from_extent
    pathes = self._get_DEMPathes_to_include(tgt_corner_coord_lonlat)
  File "/home/gfz-fe/scheffler/python/gms_preprocessing/gms_preprocessing/io/input_reader.py", line 413, in _get_DEMPathes_to_include
    sceneIDs_srtm = self.get_overlapping_DEM_tiles(tgt_corner_coord_lonlat, timeout_sec)
  File "/home/gfz-fe/scheffler/python/gms_preprocessing/gms_preprocessing/io/input_reader.py", line 382, in get_overlapping_DEM_tiles
    scenes = SpIM.getFullSceneDataForDataset(envelope=corner_coord_to_minmax(tgt_corner_coord_lonlat),
  File "/home/gfz-fe/scheffler/python/gms_preprocessing/gms_preprocessing/misc/spatial_index_mediator.py", line 253, in getFullSceneDataForDataset
    numBytes = con.recvInt()
  File "/home/gfz-fe/scheffler/python/gms_preprocessing/gms_preprocessing/misc/spatial_index_mediator.py", line 364, in recvInt
    return struct.unpack('>i', self.socket.recv(4))[0]
struct.error: unpack requires a buffer of 4 bytes