Fold.3 does have the records for the 55th Alabama Infantry, surnames A-B, they are found in the index at “Fifty-fourth Infantry: Fifty-Fifth Volunteers.”

The rub is that the records for the unit are found on the microfilm rolls listed below.

M311: Compiled Service Records of Confederate Soldiers Who Served in Organizations from the State of Alabama, 508 rolls

Roll - Description

453 54th Infantry
A-N
454 O-Z
55th Volunteers
A-B
455 C-Ha
456 He-P
457 R-Y
458 56th Partisan Rangers

Much of the fault is that the National Archives microfilmed the records in a haphazard manner. To really get the most out of Fold.3, you need to have at your finger tips, the National Archives Military Service Records, A Select Catalog of National Archives Microfilm Publications. From their index, you can usually locate the records that seem to be missing from Fold.3

I find fault with Footnote/Fold.3 for not sorting this mess out.