Serial Communication - How to read large bytes of data

I just tried again, and I could reproduce this problem with a different data set.

so the actual data is:

<aaaaaaaaaaaaaaaaaaaa
ssssssssssssssssssss
dddddddddd
ffffffffff
gggggggggg
hhhhhhhhhhhhhhhhhhhh
jjjjjjjjjjjjjjjjjjjjjjjjjjjjjj
kkkkkkkkkkkkkkkkkkkk
llllllllll
00000000000000000000
>
<111111111143444444444
44444444446666666666>
<0000000000
99999999999999999999kkkkkkkkkk
jjjjjjjjjj6666666666yyyyyyyyyy
gggggggggg3333333333>

while I only got:

This just in ... aaaaaaaaaaaaaaaaaaaa
ssssssssssssssssssss
dddddddddd
ffffffffff
gggggggggg
hhhhhhhhhhhhhhhhhhhh
jjjjjjjjjjjjjjjjjjjjjjjjjjjjjj
kkkkkkkkkkkkkkkkkkkk
llllllllll
00000000000000000000

This just in ... 111111111143444444444
44444444446666666666
This just in ... 0000000000
9333

In the beginning I thought I reached certain buffer size limit, but in this second trial, I captured much less bytes of data in compared to 1st trial, so I believe there is some other mechanism playing the magic...