Readseq identifying the wrong DATATYPE

[nurgling]

Hi there,

Having problems with readseq.jar and not finding an answer anywhere.

Input:
Amino acid .fasta alignments, truncated example:
>ALEXANDRIUM-CATENELLA_TRINITY_DN55193_C0_G1_I1_5
--SVLEQLRSSHEDIENIEKAMS-------K.......SS.......KQT.......VSCEHALKYLIE---N...K...S...KT...A...VEIYQDKDGMRTDDINAL--------Q........GDV
>DINOPHYSIS-ACUMINATA_TRINITY_DN39905_C0_G3_I1_2
---SVLEQLRSAHEDIENIEKAMS-------K.......ST.......RNT.......VACEHSLKYLID...T---K...C...KT...A...VDIYQDKDGMRSDDINAL---

command: Turn .fasta into a .nexus file
`java -jar /PATHs/readseq.jar -f17 EPrGT00050000000311.clean.aln.fa`

`head` of output .nexus file:
#NEXUS
BEGIN DATA;
DIMENSIONS NTAX=23 NCHAR=1007;
FORMAT DATATYPE=DNA INTERLEAVE MISSING=-;
[Name: ALEXANDRIUM-CATENELLA_TRINITY_DN55193_C0_G1_I1_5 Len: 1007 Check: 0]
[Name: DINOPHYSIS-ACUMINATA_TRINITY_DN39905_C0_G3_I1_2 Len: 1007 Check: 0]

Problem: DATATYPE=DNA which should be PROTEIN instead. Previously it would designate the correct datatype.
Problem is occuring on both laptop and cluster.

Questions:
Has this happened to anyone else?
Any idea what may be confusing readseq as to the DATATYPE?
Is it possible to force readseq to set the input as AAs?