Repeating Custom Tags Causes Parsing Error of Message

We are using QuicFIX J custom built functionality for parsing messages that we receive. We have custom tags with tag id in the 9000 ranges. These are allocation report messages and they can have a lot of these optional fields that we do not process, and some of them are nested and repeating. What I am seeing tis that when these tags are repeating, the QuickFIXJ is unable to read any fields after those set of tags.
Is this a known expected behaviour?

Example Message:
8=FIX.4.49=108635=AS34=183649=FCI-TNS56=CAPGROUP52=20130529-19:02:51453=2448=CPILGB2L447=B452=13802=1523=Capital Group Companies803=5448=BAMLPSWDCTM447=B452=1802=1523=Bank of America - BAMLPSWDCTM803=571=0794=3755=CPILGB2L136985417107987=09052=10137269169053=Y9057=MAGR857=054=2167=CORP6=98.86753=12460000381=12318828.2231=100.060=20130529-00:00:0075=2013052964=20130603157=166541=20180201223=1.570=27573200122=448=US828807CM76107=SIMON PROPERTY GROUP 144A LIFE SR UNSEC 1.5% 02-01-189061=49062=US828807CM769859=86181.679858=USD9874=29873=FLAT9865=EXEC9869=USD9866=09873=FLAT9865=TCOM9869=USD9866=078=379=000031467=7732620019047=2511221.880=2540000172=0169=285=1165=1781=1782=DTCYUS33783=B784=10801=0154=2528790.13742=17568.3312=013=379=000008467=7732820019047=6080320.580=6150000172=0169=285=1165=1781=1782=DTCYUS33783=B784=10801=0154=6122858742=42537.512=013=379=000078467=7732720019047=3727285.980=3770000172=0169=285=1165=1781=1782=DTCYUS33783=B784=10801=0154=3753361.73742=26075.8312=013=310=020

In this case, the allocations are not read. They start at tag 78. Right before tag 78, we see repeating tags 9865, 9869, 9866.
We have seen examples of this behaviour with other tags as well.