Obtaining all protein sequences with a particular domain architecture from Pfam
An alternative way is using the Hmmer website, and do a hmmsearch with the Pfam accession, forex. (PF02910). Navigate to the domain tab and find the domain architecture that you are interested in and press view scores. That way, only the sequences you are interested in will be downloadable under the tab downloads. 

Step-by-Step guide:

1- Go to http://www.ebi.ac.uk/Tools/hmmer/

2- Search with hmmsearch http://www.ebi.ac.uk/Tools/hmmer/search/hmmsearch

3- Use Accession search and type in PF02910

4- Navigate to Domain

5- To the right side of 
9742 sequences with domain architecture: FAD_binding_2, Succ_DH_flav_C 

Press View scores.

6- It should show (Your results have been filtered) and Query matches (9742)

7- Navigate to Download and download the sequences in the format of interest. 

8- Repeat for domain architectures of interest. 

I hope you find this helpful.

Kind Regards,

Sara