There are definitely mistakes in the census records. We don't know who reported the information (individual adult, child, or a neighbor) and at times the census taker misheard the information or skipped a line. You probably should look for additional records (or give us the names, approximate birth dates, and place so we can help). The 1950 US Census will become available in April 2022, which may help clarify the information.
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To answer your question if the census enumerators made mistakes? Sometimes yes, and without seeing the same census records that you are we can not answer that question completely.
To illustrate mistakes being made we found a Census page for a Frank Harvey age 53, African- American married to an Allie May age 30 also Africa- America at the bottom of page 7B, enumeration District 49-13, for Mayfield, Montgomery County, Mississippi. At the top of the next page (8A enumeration district 49-13, for Mayfield, Montgomery Country, Mississippi) is an entry for a Eddie Scipper age 37, white listed as son- in- law to head of household. Taken in this context, someone could assume that these two households are the same, but if you look at the “Number of household in order of visit” column the Harvey’s are household 121 and the next household visited after the Scipper’s was household 128. It is possible that these two pages are actually for 2 separate households and that other household were missed between the Harvey's and the Scipper's. The visits to these two families also occurred on two separate days.
Another item to take into consideration regarding your question is that for questions such as gender and race the enumerator didn’t always ask the individual and inferred the answer and marked on it on the page. For more information on the census we recommend checking out the NARA resource on Census Records and for additional help please contact the National Archives at Washington, DC - Textual Reference (RDT1) via email at firstname.lastname@example.org.
You may also consider looking to see how your family is documented in the previous decades' census to clarify information.
We hope that this information was helpful.
(Below are images from the National Archive Catalog for the two pages reference above.
1940 Census Population Schedules - Mississippi - Montgomery County - ED 49-13 NARA Catalog ID: https://catalog.archives.gov/id/128079946