postgres 9.5 DB corruption

Hello postgres community,
Writing again to see if there are insights on this issue. We have had infrequent but recurring corruption since upgrading from postgres 9.1 to postgres 9.5. We are presently on 9.5.16. Our DB-facing app continually performs a mixture of DML, primarily inserts and updates on two specific tables, with no single op being suspect. In the past, corruption events have produced encoding errors on COPY operations (invalid byte sequence for encoding "UTF8"). More recently, they have caused segmentation faults. We were able to take a cold backup after a recent event. SELECTing the corrupted data on our cold backup yields the following stack. Any info on a solution or how to proceed towards a solution would be much appreciated.
Thanks in advance.

(gdb) where
#0  pglz_decompress (source=source(at)entry=0xa617904 "0", slen=8139, dest=dest(at)entry=0x4268e028 "", rawsize=808452096) at pg_lzcompress.c:745
#1  0x080f3079 in toast_decompress_datum (attr=0xa6178fc) at tuptoaster.c:2210
#2  0x080f3716 in heap_tuple_untoast_attr (attr=0xa6178fc) at tuptoaster.c:183
#3  0x08440955 in pg_detoast_datum_packed (datum=<optimized out>) at fmgr.c:2270
#4  0x084145bf in text_to_cstring (t=0x7592fd2a) at varlena.c:176
#5  0x0843e874 in FunctionCall1Coll (flinfo=flinfo(at)entry=0xa614738, collation=collation(at)entry=0, arg1=arg1(at)entry=1972567338) at fmgr.c:1297
#6  0x0843fef8 in OutputFunctionCall (flinfo=0xa614738, val=1972567338) at fmgr.c:1950
#7  0x080bf84b in printtup (slot=0xa613bf4, self=0xa60d714) at printtup.c:359
#8  0x08220f9a in ExecutePlan (dest=0xa60d714, direction=<optimized out>, numberTuples=0, sendTuples=<optimized out>, operation=CMD_SELECT, planstate=0xa613974, estate=0xa6138ec) at execMain.c:1574
#9  standard_ExecutorRun (queryDesc=0xa6134e4, direction=ForwardScanDirection, count=0) at execMain.c:337
#10 0x08332c1b in PortalRunSelect (portal=portal(at)entry=0xa6114dc, forward=forward(at)entry=1 '\001', count=0, count(at)entry=2147483647, dest=dest(at)entry=0xa60d714) at pquery.c:942
#11 0x08333fa7 in PortalRun (portal=portal(at)entry=0xa6114dc, count=count(at)entry=2147483647, isTopLevel=isTopLevel(at)entry=1 '\001', dest=dest(at)entry=0xa60d714, altdest=altdest(at)entry=0xa60d714, completionTag=completionTag(at)entry=0xffd5d71c "")
    at pquery.c:786
#12 0x08330ba8 in exec_simple_query (query_string=0xa5f1754 "select * from ams.alert_attribute_bak;") at postgres.c:1096
#13 PostgresMain (argc=1, argv=0xa53dbbc, dbname=0xa53daec "ams", username=0xa53dadc "akamai") at postgres.c:4049
#14 0x080b53af in BackendRun (port=0xa584b78) at postmaster.c:4312
#15 BackendStartup (port=0xa584b78) at postmaster.c:3986
#16 ServerLoop () at postmaster.c:1705
#17 0x082d0dd7 in PostmasterMain (argc=argc(at)entry=3, argv=argv(at)entry=0xa53d2a8) at postmaster.c:1313
#18 0x080b68eb in main (argc=3, argv=0xa53d2a8) at main.c:228
(gdb)

Tom    :-)