We have a table in browser:

----------------------------------------------------------
| text1 | text2 | ...text3 .....|..... text4. ...|
|........ | .........| ----------------|------------------|
|........ | .........| .t31 .| t32 .| .t41. |.. t42 |
---------------------------------------------------------

(Sorry for spaces shrinked by parser. I changed them to dots.)
When it is exported (for example) in excel file, we have:
----------------------------------------------------------
| text1 | text2 | ...text3 .....|..... text4. ...|
|........ | .........| ----------------|------------------|
|........ | .........| .t31 .| .t41 |. t42 |
---------------------------------------------------------
All columns after header are exporting normally.
How to fix this error?
Thank you for answer!