Is there a limit on the numer of charactes used for Tab Names?

[FTong]

I am new to Appsheet (1 .5 weeks and counting).

I am having a problems when defining Enum Data Validity with a Table Column
(See Below)

ej1: TG.099.ReferenceTables[Job_Rates]
ej2:TG.999.TestTable[Job_Rates]

When I use ej1 - the field does not show up on the forms view.

When I use ej2 - the field works fine in the forms view.

Questions:

1. Is there an Appsheet limitation on the number of characters that can be used to name a Sheet/Tab (from Google Sheets?)
2. Is there a restricted name/variable that I may have tripped upon?

Notes:
1-ej1 and ej2 refer to different Data Tables (Sheets) in the same file.
2-I verified the setting of each column is the same in both Data Tables.