Yes refix and wash.
I have almost always used two bath fixing:
In Fixer bath 1, I fix for twice the clearing time, with constant agitation. For Fixer bath 2 I agitate continuously for half the total time in Fixer 1.
Typical fixing time in Fixer 1, when fresh, will be 2 minutes.
When Fixer bath 1 has fixed its maximum number of films(based on clearing time), discard it (or send it to silver recovery). Then the old Fixer 2 is the new Fixer 1 and you make up a new batch of Fixer 2.
This from The Manual of Photography (fifth edition):
>>>The fixing bath removes the residual silver halide by transforming it into complex sodium argentothiosulphates. These substances are not particularly stable and, after fixation, must be removed from the emulsion by washing. If left in the emulsion, they will in time break down to form an all-over yellowish-brown stain of silver sulphide.
In the presence of a high concentration of soluble silver, or low concentration of free thiosulphate, as when the fixing bath is nearing exhaustion, there is a tendency for the complex sodium argentothio-sulphates to be "adsorbed", or "mordanted", to the emulsion, in which condition they are difficult to remove by washing. Fixation in an exhausted bath is therefore attended by risk of subsequent staining, as a result of the breakdown of the silver complexes remaining in the emulsion, however efficient the washing process.
To avoid the danger of such staining, the best practice is to use two fixing baths in succession, according to the following procedure. Initially, two fresh baths are prepared and materials are left in the first bath until they are just clear, being then transferred to the second bath for an equal period. In the course of time, the clearing time in the first bath - which is doing practically all the work of fixation - will become inconveniently long. When clearing requires, say, double the time required in a fresh bath, the first bath should be discarded and replaced by the second, which, in turn, should be replaced by a completely fresh bath. This process is repeated as required, with the result that the second bath is always relatively fresh. Adoption of this procedure ensures that all films leave the second fixing bath in good condition from the point of view of subsequent permanence; as good in fact as if they had been fixed throughout in a fresh bath. The method is also economical, in that it enables all the fixer in turn to be worked to a point far beyond that at which a single bath would have to be discarded.<<<