SQL Server 2016 splits rows in flat file destination

An SSIS job running with an OLE DB connection to a SQL Server 2008 produces a flat file destination output like this:

905574|012470,097566,298605,334988,426155,481002,...
910219|029929,149841,326495,461291
933447|067516
943449|053096,092330,249222,300504,329626,386116,...
944688|017507,071064,289347,319367,356738,474931,...
954567|033549,083460,294846,313324,446125,476221,...
961179|001630,043896,184759,326832,411758,445063,...
971664|048997,098448,
974104|085329,136985,204911,300600,356153
997138|032756,166485,214313,412516,481333,495417,...
...

The same SSIS job running with an OLE DB connection to a SQL Server 2016 produces a flat file destination output like this:

905574|012470,097566,298605,334988,426155,481002,...
910219|029929,149841,326495,461291
933447|067516
943449|053096,092330,249222,300504
943449|329626,386116,...
944688|017507,071064,289347,319367,356738,474931,...
954567|033549,083460,294846,313324,446125,476221,...
961179|001630,043896,184759,326832,411758,445063,...
971664|048997,098448,
974104|085329,136985,204911,300600,356153
997138|032756,166485,214313
997138|412516,481333,495417,...
...

The "..." above just means there is more data in the real files. The longest rows can have 3,000 or more six digit entries after the |. The shortest rows can have one six digit entry after the |.

Running with a connection to SQL Server 2016 produces output where every few lines a row is split into multiple rows. For example, the rows beginning with943449 and 997138 in the SQL Server 2008 example has everything after the | split into two rows in the SQL Server 2016 example.

The source data is exactly the same on the two databases. This is part of a conversion project from SQL Server 2008 to SQL Server 2016.

The output columns for the destination file have the same settings. What else can I check?

Thanks.